International Credit Card (VISA/MASTER) Payment API

About 4188 wordsAbout 14 min

Before reading this API documentation, be sure to review the API Description Guide

PCI DSS (Payment Card Industry Data Security Standard) strictly prohibits embedding credit card input pages in WebView or iframe for the following reasons:

PCI Compliance: Direct violation of PCI DSS requirements
Security Risks: WebView and iframe may not provide sufficient security isolation
Man-in-the-Middle Attacks: Malicious applications may intercept or tamper with payment data
Phishing Risks: Cannot ensure users are entering sensitive information in a trusted environment

Device Environment Requirements

Check Your Device and Browser Settings

If you cannot see the wallet you want on the payment page, your device or browser may not meet the following Apple Pay or Google Pay requirements.

You must have at least one card in your wallet.
You must use compatible Apple Pay devices and Google Pay devices.
You must use HTTPS and supported browsers to test the wallet you are testing.
Allow applicable browsers to access your wallet.
- Chrome: Settings > Autofill and passwords > Payment methods > Allow sites to check if you have saved payment methods
- Safari: Settings > Advanced > Allow websites to check for Apple Pay and Apple Card
Do not use Chrome incognito window or Safari private window.
Confirm you are operating in supported Apple Pay and Google Pay regions.
For Apple Pay, confirm your device supports biometric authentication.

Supported Browsers

Desktop Browsers

Chrome 38+
Safari 10.1+
Firefox 29+
Edge 15+
Opera 25+

Mobile Browsers

iOS Safari 9+ and other browsers and web views using the system-provided WebKit engine
Android Chrome 38+
Samsung Browser 7.1+

Other Notes

For browsers not explicitly supported, we limit support as follows:

Requires browser support for TLS 1.2
Requires a sufficiently modern browser to support Promises in JavaScript
We respond to error reports but do not actively test other browsers

Regional Restrictions

Unsupported Regions List

AD - Andorra

AE - United Arab Emirates

AF - Afghanistan

AG - Antigua and Barbuda

AI - Anguilla

AL - Albania

AM - Armenia

AO - Angola

AQ - Antarctica

AR - Argentina

AS - American Samoa

AW - Aruba

AX - Åland Islands

BA - Bosnia and Herzegovina

BB - Barbados

BD - Bangladesh

BF - Burkina Faso

BH - Bahrain

BI - Burundi

BJ - Benin

BL - Saint Barthélemy

BM - Bermuda

BN - Brunei

BQ - Bonaire, Sint Eustatius, and Saba

BS - Bahamas

BT - Bhutan

BV - Bouvet Island

BW - Botswana

BY - Belarus

BZ - Belize

CC - Cocos (Keeling) Islands

CD - Democratic Republic of the Congo

CF - Central African Republic

CG - Republic of the Congo

CI - Ivory Coast

CK - Cook Islands

CM - Cameroon

CO - Colombia

CU - Cuba

CV - Cape Verde

CW - Curaçao

CX - Christmas Island

CY - Cyprus

DJ - Djibouti

DM - Dominica

DO - Dominican Republic

DZ - Algeria

EC - Ecuador

EE - Estonia

EG - Egypt

EH - Western Sahara

ER - Eritrea

ET - Ethiopia

FJ - Fiji

FK - Falkland Islands

FM - Federated States of Micronesia

FO - Faroe Islands

GA - Gabon

GD - Grenada

GE - Georgia

GF - French Guiana

GG - Guernsey

GH - Ghana

GI - Gibraltar

GL - Greenland

GM - Gambia

GN - Guinea

GP - Guadeloupe

GQ - Equatorial Guinea

GS - South Georgia and the South Sandwich Islands

GT - Guatemala

GW - Guinea-Bissau

HK - Hong Kong

HM - Heard Island and McDonald Islands

HN - Honduras

HT - Haiti

ID - Indonesia

IL - Israel

IM - Isle of Man

IN - India

IO - British Indian Ocean Territory

IQ - Iraq

IR - Iran

JM - Jamaica

JO - Jordan

JP - Japan

KE - Kenya

KH - Cambodia

KI - Kiribati

KM - Comoros

KN - Saint Kitts and Nevis

KP - North Korea

KR - South Korea

KW - Kuwait

KY - Cayman Islands

KZ - Kazakhstan

LA - Laos

LB - Lebanon

LC - Saint Lucia

LI - Liechtenstein

LK - Sri Lanka

LR - Liberia

LS - Lesotho

LV - Latvia

LY - Libya

MD - Moldova

ME - Montenegro

MF - Saint Martin (French part)

MG - Madagascar

MH - Marshall Islands

MK - North Macedonia

ML - Mali

MM - Myanmar

MN - Mongolia

MP - Northern Mariana Islands

MQ - Martinique

MR - Mauritania

MS - Montserrat

MU - Mauritius

MV - Maldives

MW - Malawi

MY - Malaysia

MZ - Mozambique

NA - Namibia

NC - New Caledonia

NE - Niger

NF - Norfolk Island

NG - Nigeria

NI - Nicaragua

NP - Nepal

NR - Nauru

NU - Niue

OM - Oman

PA - Panama

PE - Peru

PF - French Polynesia

PG - Papua New Guinea

PH - Philippines

PK - Pakistan

PM - Saint Pierre and Miquelon

PN - Pitcairn Islands

PR - Puerto Rico

PS - Palestine

PW - Palau

RE - Réunion

RU - Russia

RW - Rwanda

SA - Saudi Arabia

SB - Solomon Islands

SC - Seychelles

SD - Sudan

SH - Saint Helena

SJ - Svalbard and Jan Mayen

SK - Slovakia

SL - Sierra Leone

SM - San Marino

SN - Senegal

SO - Somalia

SR - Suriname

SS - South Sudan

ST - São Tomé and Príncipe

SV - El Salvador

SX - Sint Maarten (Dutch part)

SY - Syria

SZ - Eswatini

TC - Turks and Caicos Islands

TD - Chad

TF - French Southern Territories

TG - Togo

TH - Thailand

TK - Tokelau

TL - East Timor

TM - Turkmenistan

TN - Tunisia

TO - Tonga

TR - Turkey

TT - Trinidad and Tobago

TV - Tuvalu

TW - Taiwan

TZ - Tanzania

UA - Ukraine

UG - Uganda

UM - United States Minor Outlying Islands

UY - Uruguay

UZ - Uzbekistan

VA - Vatican City

VC - Saint Vincent and the Grenadines

VE - Venezuela

VG - British Virgin Islands

VI - U.S. Virgin Islands

VN - Vietnam

VU - Vanuatu

WF - Wallis and Futuna

WS - Samoa

YE - Yemen

YT - Mayotte

ZA - South Africa

ZM - Zambia

ZW - Zimbabwe

HaiPay.js Integration (Apple Pay & Google Pay)

HaiPay provides a convenient Apple Pay and Google Pay payment integration solution that allows you to quickly integrate payment functionality into web pages through simple configuration.

Import HaiPay script ([https://cdn.jsdelivr.net/gh/hpth/payment/cashier/js/applePayGooglePay_1.0.0.js])
Page structure requirements
- Payment button container: Used for rendering Apple Pay/Google Pay buttons.
- Error message container: Used to display error messages during the payment process (such as parameter errors, payment failures, etc.).
Quick integration example

<script src="https://cdn.jsdelivr.net/gh/hpth/payment/cashier/js/applePayGooglePay_1.0.0.js"></script>

<div id="appId">
  <div id="applePay-googlePay"></div>
  <div id="error-message-pay"></div>
</div>

const elements = new HaiPay({
  env: 'test',
  orderNo: '6cgjnxvc6kdb',
  buttonContainerId: 'applePay-googlePay',
  errorContainerId: 'error-message-pay',
  onCallback: (status) => {},
  onReady: () => {},
  onError: (error) => {}
});
elements.createPay();

Parameter description
- 1. Initialization configuration parameters (HaiPay constructor parameters)

Parameter Name	Required	Type	Description
env	Yes	String	Environment type, optional values: - test: Test environment (for integration testing) - prod: Production environment (for live use)
orderNo	Yes	String	Platform order number
buttonContainerId	Yes	String	Payment button container DOM ID, do not include # prefix
errorContainerId	No	String	Error message container DOM ID, do not include # prefix
buttonType	No	String	Button text type, default value buy, optional values: - plain: "Display payment logo only, no text" - add-money: "Add funds" - book: "Book" - buy: "Buy" (default) - check-out: "Checkout" - contribute: "Donate" - order: "Order" - reload: "Reload" - rent: "Rent" - subscribe: "Subscribe" - support: "Support" - tip: "Tip" - top-up: "Top-up"
buttonTheme	No	String	Button theme style, default value black, optional values: - black: Black background - white: White background
buttonHeight	No	number	Button height, default value 50
onCallback	No	function	Order status callback function, parameter is status code: - Success: "2"/"4"/"5" - Failure: "3"
onReady	No	function	Payment button rendering completion callback function
onError	No	function	Error message callback function

1. Common error types and solutions

Error Message	Error Cause	Solution
Missing required parameters: env, orderNo	Missing required initialization parameters	Check if parameters like env, orderNo are passed
The env parameter must be test or prod	Invalid env parameter value	Change env to test or prod
Button container does not exist: #xxx	Payment button container ID does not exist	Confirm if the payment region is within the supported range, or switch to test environment
Unsupported region: CN	Production environment does not support China region	Check if there is a DOM element with the corresponding ID in the page

Transaction Limits

Transaction Type	Limit (USD)
Collection	0.99-1000

Collection API

1. Collection Application

Brief Description:

Create a collection order

URL:

USD: /usd/collect/apply Note: appId for USD, amount in USD, settlement in USD

Parameters:

Parameter Name	Required	Type	Description
appId	Yes	Long	Business ID (obtained from backend, must pass corresponding business ID based on currency in URL)
orderId	Yes	String	Merchant order number (must be unique, length not exceeding 48)
name	Yes	String	User name, recommended to use real name, format: firstName and lastName separated by space, example: Donald John Trump
phone	Yes	String	Real phone number (format reference Phone Number Format)
email	Yes	String	Real email address
amount	Yes	String	Transaction amount (accurate to two decimal places; do not add punctuation, e.g., ",")
payType	Yes	String	Payment method type
inBankCode	Yes	String	Payment method code
clientIp	No	String	Client IP address
callBackUrl	Yes	String	URL to redirect after successful payment
callBackFailUrl	Yes	String	URL to redirect after failed payment
notifyUrl	No	String	Callback URL
subject	Yes	String	Payment remark
body	No	String	Remark details
partnerUserId	Yes	String	Unique user identifier (e.g., userId), used for risk control, must be real and valid, otherwise it will affect transactions. Format requirements: digits, uppercase and lowercase letters or common symbols -~!@#$%&*()_.
sign	Yes	String	Signature

request

{
  "appId": 1054,
  "orderId": "M233323000059",
  "amount": "300",
  "phone": "09230219312",
  "email": "23423@qq.com",
  "name": "test",
  "inBankCode": "USA",
  "payType": "BANK_TRANSFER",
  "partnerUserId": "149597870",
  "sign": "af0gAHkUOyYHu9owQp8NJ4mPEeUW4vuJcjdxqLIzrVw8AvpLSjD1DXupReSG/CyuSkFRyiIvCp5u703AuGGmfgD2gKDH3Ywau41bAbG2jnHJ8mtjiSJ5iWUzanyd4Kr7d1+rETbzUl7/BkW3t0X8UUFdqpxwG8DPUjAwUKfplWDHV7koG51Ozexd80DCsmW6eWdouAZ1uNXGLYmV3ftE3BmfNRtuv1C5bfTJWrTEIOxbF6g2uYOFZTlIgrQgd7/2PsAYwQQXNz8Q8CYl4OxqCv4pXJxaLWPbR5tqZu9og5kn32C9aHW/NlU1y39vzz+4ef81yPAqUV9oHlSMSPrMmw=="
}

response

{
  "status": "1",
  "error": "00000000",
  "msg": "",
  "data": {
    "orderId": "M233323000059",
    "orderNo": "6023071013539074",
    "payUrl": "",
    "clientToken": "",
    "sign": "YEoA8Y2JzQFGVzwJSqmemm1Kfv/bfyIfCqv2dp7RNzT5B72AQvdD+nt2nR4sL1HWscvmNHyVt5ovAi7MMhy3ziih/sMph+wPx4YjH3W1h5DyBvSlWvaKfKrK5ViomZ0pPYWydwRHnnRnicxToHK9S6qtSy7Q73O0hdz4hJ9p41Th3ycBl2Q9SeqSZYSY1ohcPDhdyRf2y0prb8rHgpBKzxZ5BKX/1bsE9OmsSEHAEYT8OGgko6aNe8XPAhr4G48cpWTftvnGQuzh0O65nuZRI/PF+Axt2zJCVbFHDDSREI9NlAT82ebDqhlVdxQzKE67D1nxgjb3dPmDUYHOBpmwxQ=="
  }
}

Response data parameter description

Parameter Name	Type	Description
orderId	String	Merchant order number (must be unique)
orderNo	String	Platform order number
payUrl	String	Payment link
clientToken	String	Client token used in JavaScript Web SDK (see HaiPaySDK.js)
sign	String	Signature

2. Collection Application MIT Mode

Brief Description:

Create MIT mode collection order

URL:

USD: /usd/mit/apply Note: appId for USD, amount in USD, settlement in USD

Parameters:

Parameter Name	Required	Type	Description
appId	Yes	Long	Business ID (obtained from backend, must pass corresponding business ID based on currency in URL)
orderId	Yes	String	Merchant order number (must be unique, length not exceeding 48)
name	No	String	User name, recommended to use real name, format: firstName and lastName separated by space, example: Donald John Trump
phone	No	String	Real phone number (format reference Phone Number Format)
email	No	String	Real email address
amount	Yes	String	Transaction amount (accurate to two decimal places; do not add punctuation, e.g., ",")
payType	Yes	String	Payment method type
inBankCode	Yes	String	Payment method code
clientIp	No	String	Client IP address
callBackUrl	Yes	String	URL to redirect after successful payment
callBackFailUrl	Yes	String	URL to redirect after failed payment
notifyUrl	No	String	Callback URL
subject	Yes	String	Payment remark
body	No	String	Remark details
partnerUserId	Yes	String	Unique user identifier (e.g., userId), used for risk control, must be real and valid, otherwise it will affect transactions. Format requirements: digits, uppercase and lowercase letters or common symbols -~!@#$%&*()_.
tokenID	No	String	Payment token, not required for first transaction, required for subsequent active deductions, obtained through callback
token	No	String	Apple Pay / Google Pay Token, required for first transaction, How to get?
sign	Yes	String	Signature

request

{
  "appId": 1054,
  "orderId": "M233323000059",
  "amount": "300",
  "phone": "09230219312",
  "email": "23423@qq.com",
  "name": "test",
  "inBankCode": "USA",
  "payType": "BANK_TRANSFER",
  "partnerUserId": "149597870",
  "sign": "af0gAHkUOyYHu9owQp8NJ4mPEeUW4vuJcjdxqLIzrVw8AvpLSjD1DXupReSG/CyuSkFRyiIvCp5u703AuGGmfgD2gKDH3Ywau41bAbG2jnHJ8mtjiSJ5iWUzanyd4Kr7d1+rETbzUl7/BkW3t0X8UUFdqpxwG8DPUjAwUKfplWDHV7koG51Ozexd80DCsmW6eWdouAZ1uNXGLYmV3ftE3BmfNRtuv1C5bfTJWrTEIOxbF6g2uYOFZTlIgrQgd7/2PsAYwQQXNz8Q8CYl4OxqCv4pXJxaLWPbR5tqZu9og5kn32C9aHW/NlU1y39vzz+4ef81yPAqUV9oHlSMSPrMmw=="
}

response

{
  "status": "1",
  "error": "00000000",
  "msg": "",
  "data": {
    "orderId": "M233323000059",
    "orderNo": "6023071013539074",
    "payUrl": "",
    "clientToken": "",
    "sign": "YEoA8Y2JzQFGVzwJSqmemm1Kfv/bfyIfCqv2dp7RNzT5B72AQvdD+nt2nR4sL1HWscvmNHyVt5ovAi7MMhy3ziih/sMph+wPx4YjH3W1h5DyBvSlWvaKfKrK5ViomZ0pPYWydwRHnnRnicxToHK9S6qtSy7Q73O0hdz4hJ9p41Th3ycBl2Q9SeqSZYSY1ohcPDhdyRf2y0prb8rHgpBKzxZ5BKX/1bsE9OmsSEHAEYT8OGgko6aNe8XPAhr4G48cpWTftvnGQuzh0O65nuZRI/PF+Axt2zJCVbFHDDSREI9NlAT82ebDqhlVdxQzKE67D1nxgjb3dPmDUYHOBpmwxQ=="
  }
}

Response data parameter description

Parameter Name	Type	Description
orderId	String	Merchant order number (must be unique)
orderNo	String	Platform order number
payUrl	String	Payment link
clientToken	String	Client token used in JavaScript Web SDK (see HaiPaySDK.js)
sign	String	Signature

3. Collection Query

Brief Description:

Query collection order

URL:

USD: /usd/collect/query

Parameters:

Parameter Name	Required	Type	Description
appId	Yes	Long	Business ID (obtained from backend, must pass corresponding business ID based on currency in URL)
orderId	Yes	String	Merchant order number
orderNo	No	String	Platform order number (faster response)
sign	Yes	String	Signature

request

{
  "appId": 1054,
  "orderId": "M22222000028",
  "sign": "EmyJGm3ELzG4FsOd0Krs9ncbSjo4oTGuXWML+7djYla3+VAwd9wS17z38p/7U2ZAjroO04XrE7YXcB1o76Dtyipj3h3bJzs7FYma1QNkMUdt9hh7m8U6hMsMQX7vIWHtXNwz4pbTSC75+kQWXaCew7KoE6LXECdJU8AISgNgeki2TK9R0pCfshr0Z2SZBPeuT6OvIH5LdmqgdZhuqnffGU2qnXk4KMkO848e6/WALLBR+LE1wyKHfPnYVcuKSMVYxkvKyyIL5JIPEgW0o5bh4RCbaUn3NZtyYwrU1uQ3ZDFRThm9j6XAQP+LBlmq3nOePqBtp/VDVarRaV+7FbQg3A=="
}

response

{
  "status": "1",
  "error": "00000000",
  "msg": "",
  "data": {
    "orderId": "M22222000028",
    "orderNo": "6023042811314347",
    "amount": "50.00",
    "actualAmount": "0.00",
    "fee": "0.00",
    "status": 1,
    "sign": "fP433ygWVDLVGxYkVnIJj7riGq0U3vyVX+MbBAImxfGLZkZcEAHVEoVYuULZSmXAAXKRSyd67WlDNm+24pougM54ofAoH4HMtCL2tfCoBReFyz3z02AGKkrKE2xWhSpWoqfQoBvzwuN5iGMMu0s9Q1YvqiwJ8WDVIENnmiIyD8qDJN7caHTW2US14/faG+69AvnuIgJ/nu7/jogOlgEYdZdVYU7gcRDE+d47KjlFGswQkJ/h/uzV7cWtUqrtOO7ZnZ3/z33Xx8awokX36QoYcPSWAU0h+Ij9O9402HNhm1eTbYcLU0uI/z8xCAtyAI/tTyiFijpiNlxUKQj+zKsILw=="
  }
}

Response data parameter description

Parameter Name	Type	Description
orderId	String	Merchant order number (must be unique)
orderNo	String	Platform order number
amount	String	Transaction amount
actualAmount	String	Amount received
fee	String	Handling fee
status	Integer	Status (0 - Not started, 1 - In progress, 2 - Success (final), 3 - Failure (final), -1 - Pending confirmation)
payTime	String	Payment success time (present when status=2) (local time), format: yyyy-MM-dd HH:mm:ss
errorMsg	String	Payment failure reason (present when status=3)
sign	String	Signature

4. Refund Application

Brief Description:

Initiate a refund operation for the original credit card transaction order. Please pay attention to the status values returned synchronously. It is recommended to use the query interface for status checks.

URL:

USD: /usd/refund/apply

Parameters:

Parameter Name	Required	Type	Description
appId	Yes	Long	Business ID (obtained from backend, must pass corresponding business ID based on currency in URL)
orderId	Yes	String	Merchant refund application order number (new merchant order number, cannot use original collection merchant order number)
orderNo	Yes	String	Platform order number (original collection platform order number returned)
sign	Yes	String	Signature

Response data parameter description

Parameter Name	Type	Description
appId	String	Business ID
orderNo	String	Platform order number (original collection platform order number returned)
orderId	String	Merchant refund application order number
refundNo	String	Platform refund number for this refund
status	String	Refund status: 1 indicates refund application success, 0 indicates processing, 2 indicates failure. Initially returns processing, status needs to be checked via query interface later
errorMsg	String	Error message (may not always have a value)
sign	String	Signature

5. Refund Query

Brief Description:

Query the result of the refunded order.

URL:

USD: /usd/refund/refundQuery

Parameters:

Parameter Name	Required	Type	Description
appId	Yes	Long	Business ID (obtained from backend, must pass corresponding business ID based on currency in URL)
orderId	No	String	Merchant refund application order number
refundNo	No	String	Platform refund number (platform order number returned when refund was applied, if provided, prioritize checking this field)
sign	Yes	String	Signature

Response data parameter description

Parameter Name	Type	Description
appId	String	Merchant order number (must be unique)
orderNo	String	Platform order number (original collection platform order number)
orderId	String	Merchant application order number
refundNo	String	Platform refund number
status	String	Refund status: 1 indicates refund application success, 0 indicates processing, 2 indicates failure. Refund result is based on this status
errorMsg	String	Error message (may not always have a value)
sign	String	Signature

6. Payment Methods

Currency	Payment Type (payType)	Payment Code (inBankCode)	Limits	Status	Description
USD	BANK_TRANSFER	CREDIT_CARD	0.99-1000	Available	VISA
USD	BANK_TRANSFER	CREDIT_CARD	0.99-1000	Available	MasterCard
USD	BANK_TRANSFER	CREDIT_CARD	0.99-1000	Available	JCB
USD	EWALLET	GOOGLE_PAY	0.99-1000	Available	Google Pay
USD	EWALLET	APPLE_PAY	0.99-1000	Available	Apple Pay

7. Test Card Numbers

Warning

For use in test environment only

Simulate Successful Payment

Use the following test card numbers, enter any CVC (3-digit number) and expiration date (future date) to simulate successful payment:

Card Number 1: 4242424242424242

Simulate Payment Failure

Use the following test card numbers with invalid data to simulate payment failure:

Card Number 1: 4000000000009995
Invalid month: 13
Invalid CVV: 99

8. MIT (Merchant Initiated Transaction) Mode Description

MIT (Merchant Initiated Transaction)
Refers to transactions that merchants can initiate without the user being present after the user completes a one-time payment authorization.
This mode is widely used in business scenarios such as subscription payments, installment payments, membership renewals, delayed deductions, etc.

Basic Process

User Authorization
- User enters payment information during the first payment and completes necessary identity verification.
- Merchant saves the user's payment credentials for subsequent deduction requests.
Merchant-Initiated Deduction
- Merchant directly uses saved payment credentials to initiate deduction requests based on agreed cycles or conditions.
- Since the transaction is an offline scenario (off-session), meaning the user is not involved in the transaction, the system will complete processing based on user authorization and compliance requirements.
Authentication Requirements
- In most cases, transactions will complete directly.
- If the issuing bank or risk control system requires re-verification, the transaction may enter a pending user confirmation state, requiring user supplementary verification to complete.

Mode Features

Enhanced Experience: Users don't need to manually enter payment information each time.
Compliant and Secure: Meets international payment regulations and Strong Customer Authentication (SCA) requirements.
Wide Application: Suitable for subscription billing, auto-renewal, installment deductions, delayed settlement, etc.

MIT Flow Diagram

9. Apple Pay / Google Pay Token Acquisition Method Description

Online Demo (Test Environment, No Real Charges)

Apple Pay && Google Pay

Integration Process

No need to apply for an Apple Pay or Google Pay developer account — HaiPay handles it for you.
Include the JavaScript script ([https://js.stripe.com/v3/])
Page structure requirements:
- Payment button container: used for rendering the Apple Pay / Google Pay button.
Quick integration example

<script src="https://js.stripe.com/v3"></script>

<div id="appId">
  <div id="applePay-googlePay"></div>
</div>

      initApplePayGooglePay() {
            const stripe = Stripe('A key is required — please contact HaiPay to obtain it.'); //This key is not shared between production and testing environments.
            const paymentRequest = stripe.paymentRequest({
            country: "HK",
            currency: "usd",
            total: {
                label: "Haipay",
                amount: 0.99 * 100, // The unit is cents.
            },
            requestPayerName: true,
            requestPayerEmail: true,
            });

            // Use `paymentRequestButton` to create an Apple Pay / Google Pay button.
            const elements = stripe.elements();
            const prButton = elements.create("paymentRequestButton", {
               paymentRequest: paymentRequest,
            });

            // Check whether the browser supports Apple Pay or Google Pay.
            paymentRequest.canMakePayment().then((result) => {
                if (result && (result.applePay || result.googlePay)) {
                    prButton.mount("#applePay-googlePay");
                } else {
                    document.getElementById("applePay-googlePay").style.display = "none";
                    document.getElementById("applePay-googlePay-not-supported").style.display = 'block';
                }
            });

            paymentRequest.on("paymentmethod", async (ev) => {
                //`ev.paymentMethod.id` is the required token, which should be passed as a parameter when calling the `/usd/mit/apply` API.
            });
          }

Full code reference (JavaScript)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, viewport-fit=cover"/>
    <meta name="description" content="You have a payment link that needs to be paid. Please click the link below to make the payment." />
    <title>Google Pay and Apple Pay Demo</title>
    <script src="https://cdn.tailwindcss.com"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jsrsasign/8.0.20/jsrsasign-all-min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.6.10/vue.min.js"></script>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/element-ui/2.15.14/theme-chalk/index.min.css">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/element-ui/2.15.14/index.js"></script>    
    <script src="https://js.stripe.com/v3/"></script>

    
    <style type="text/tailwindcss">
        @layer utilities {
            .apple-pay-button {
                background-color: black;
                color: white;
                border-radius: 9999px;
                padding: 12px 24px;
                font-size: 17px;
                font-weight: 500;
                cursor: pointer;
                transition: background-color 0.2s;
                display: inline-flex;
                align-items: center;
                justify-content: center;
            }
            .apple-pay-button:hover {
                background-color: #333;
            }
            .apple-pay-button img {
                margin-right: 8px;
                height: 20px;
            }
        }
      .content {
        width: 100%;
        max-width: 600px;
        background: #fff;
        box-sizing: border-box;
        box-shadow: 0 0 calc(8.53333vmin / 32 * 8) #ccc;
        padding:calc(8.53333vmin / 32 * 20) calc(8.53333vmin / 32 * 10) calc(8.53333vmin / 32 * 10);
        margin: 0 auto 20px;
        border-radius: calc(8.53333vmin / 32 * 6);
      }
    </style>
</head>
<body class="bg-gray-50 font-sans">
    <div id="app">
        <div class="container mx-auto px-4 py-12 max-w-4xl">
            <header class="mb-10 text-center">
                <h1 class="text-3xl font-bold text-gray-900 mb-2">Google Pay And Apple Pay Demo</h1>
                <p class="text-gray-600">Experience a safe and fast payment method.</p>
            </header>

         <div class="content">
            <el-form ref="form" :rules="rules" :model="form">
                <el-form-item label="appId" prop="appId">
                  <el-input v-model="form.appId" placeholder="Please enter the appId." />
                </el-form-item>
                <el-form-item label="amount" prop="amount">
                  <el-input v-model="form.amount" placeholder="Please enter the amount." />
                </el-form-item>
                <el-form-item label="phone" prop="phone">
                  <el-input v-model="form.phone" placeholder="Please enter the phone." />
                </el-form-item>
                <el-form-item label="email" prop="email">
                  <el-input v-model="form.email" placeholder="Please enter the email." />
                </el-form-item>
                <el-form-item label="key" prop="key">
                  <el-input v-model="form.key" placeholder="Please enter the key." />
                </el-form-item>
                <el-form-item label="privateKey" prop="privateKey">
                  <el-input v-model="form.privateKey" placeholder="Please enter the privateKey."  type="textarea" resize="none" :autosize="{ minRows: 4, maxRows: 10 }"  />
                </el-form-item>
            </el-form>  
            </div>


            <div class="text-center">
                
                <div id="applePay-googlePay"></div>
                
                <div id="applePay-googlePay-not-supported" class="text-gray-500 mb-6 hidden">
                    <p><i class="fa fa-info-circle mr-2"></i>This device does not support Google Pay or Apple Pay.</p>
                </div>
                
            </div>
        </div>
    </div>

  <script>
      new Vue({
        el: "#app",
        data() {
          return {
             form: {
                token: '',
                appId: ,
                orderId: Date.now(),
                amount: "0.99",
                phone: "18801234567",
                email: "test@haipay.tech",
                name: "Haipay",
                inBankCode: "APPLE_PAY",
                payType: "EWALLET",
                partnerUserId: Date.now(),
                key: '',
                privateKey: ''
            },
            rules: {
              appId: [
                { required: true, trigger: 'blur' }
              ],
              amount: [
                { required: true, trigger: 'blur' }
              ],
              phone: [
                { required: true, trigger: 'blur' }
              ],
              email: [
                { required: true, trigger: 'blur' }
              ],
              name: [
                { required: true, trigger: 'blur' }
              ],
              key: [
                { required: true, trigger: 'blur' }
              ],
              privateKey: [
                { required: true, trigger: 'blur' }
              ],
            },
            baseURL: 'https://uat-interface.haipay.asia',
            isH5: true,
            applePayButton: null,
          };
        },
        computed: {},
        created() {
          this.isMobileDevice()
          this.applePayButton = document.getElementById('applePay-googlePay');
          this.initApplePay()
        },
        methods: {
          isMobileDevice() { 
            let self = this
            if(typeof window.orientation !== 'undefined'){
              self.isH5 = true
            } else {
              self.isH5 = false
            }
          },
          initApplePay() {
            const self = this
            const stripe = Stripe('A key is required — please contact HaiPay to obtain it.'); //This key is not shared between production and testing environments.
            const paymentRequest = stripe.paymentRequest({
            country: "HK",
            currency: "usd",
            total: {
                label: "Haipay",
                amount: Number(self.form.amount) * 100, // The unit is cents.
            },
            requestPayerName: true,
            requestPayerEmail: true,
            });

            // Use `paymentRequestButton` to create an Apple Pay / Google Pay button.
            const elements = stripe.elements();
            const prButton = elements.create("paymentRequestButton", {
               paymentRequest: paymentRequest,
            });

            // Check whether the browser supports Apple Pay or Google Pay.
            paymentRequest.canMakePayment().then((result) => {
                if (result && (result.applePay || result.googlePay)) {
                    prButton.mount("#applePay-googlePay");
                } else {
                    document.getElementById("applePay-googlePay").style.display = "none";
                    document.getElementById("applePay-googlePay-not-supported").style.display = 'block';
                }
            });

            paymentRequest.on("paymentmethod", async (ev) => {
                if(ev.walletName === 'googlePay') {
                  self.form.inBankCode = 'GOOGLE_PAY'
                } else if(ev.walletName === 'applePay') {
                  self.form.inBankCode = 'APPLE_PAY'
                }
                self.form.token = ev.paymentMethod.id //`ev.paymentMethod.id` is the required token, which should be passed as a parameter when calling the `/usd/mit/apply` API.
                const requestData = {
                    headers: { 'content-type': 'application/json' },
                    body: self.form
                };
                    const signedBody = self.generateSign(requestData);
                    const response = await fetch(`${self.baseURL}/usd/mit/apply`,
                        {
                            method: 'POST',
                            headers: {
                            'Content-Type': 'application/json',
                            },
                            body: signedBody
                        });
                    const res = await response.json()
                    if(res.status === '1') {
                        self.orderNo = res.data.orderNo
                        if(self.isH5) {
                            window.location.href = res.data.payUrl
                        }else {
                            window.open(res.data.payUrl, "_blank");
                        }
                    }

                ev.complete("success");
            });
          },
         generateSign(requestData) {
            let param = {};
            if (requestData.body) {
                const contentType = requestData.headers['content-type'] || '';
                if (contentType.toLowerCase().includes('application/json')) {
                    try {
                        const jsonData = typeof requestData.body === 'string' 
                            ? JSON.parse(requestData.body) 
                            : requestData.body;
                        
                        for (let key in jsonData) {
                            if (jsonData[key] !== '') {
                                param[key] = jsonData[key];
                            }
                        }
                    } catch (e) {
                        console.log('The request body is not in JSON format.');
                    }
                }
            }

            const sortedKeys = Object.keys(param)
                .filter(key => !['privateKey', 'sign', 'key'].includes(key))
                .sort();
            const paramString = sortedKeys.map(key => `${key}=${param[key]}`).join('&');

            let body = typeof requestData.body === 'string' 
                ? requestData.body 
                : JSON.stringify(requestData.body);
            let jsonData = JSON.parse(body);
            let key = jsonData.key;
            
            const stringSignTemp = `${paramString}&key=${key}`;
            console.log('signstring:', stringSignTemp);

            let privateKey = `
        -----BEGIN PRIVATE KEY-----
        ${jsonData.privateKey}
        -----END PRIVATE KEY-----
            `.trim();

            // sign
            const sig = new KJUR.crypto.Signature({ alg: 'SHA256withRSA' });
            sig.init(privateKey);
            sig.updateString(stringSignTemp);
            const signatureHex = sig.sign();
            const sign = hextob64(signatureHex);

            // add sign to request body
            jsonData.sign = sign;
            return JSON.stringify(jsonData);
         },
        },
      });
    </script>
</body>
</html>