I solve the issue the way it works is you have received a Client ID on your Phone Pe Dashboard. You have to integrate it via their V2 API.

Standard checkout integration: https://developer.phonepe.com/v1/docs/common-links-pg-v2-standard-checkout/

PAY API (Standard Checkout)

Authorization – https://developer.phonepe.com/v1/reference/authorization-standard-checkout Initiate Payment – https://developer.phonepe.com/v1/reference/initiate-payment-standard-checkout

Response Handling

Order Status – https://developer.phonepe.com/v1/reference/order-status-standard-checkout-1 Handling Webhooks – https://developer.phonepe.com/v1/reference/handling-webhooks-standard-checkout-1

PG Refund

Refund – https://developer.phonepe.com/v1/reference/refund-api-standard-checkout Refund Status – https://developer.phonepe.com/v1/reference/refund-status-standard-checkout