how-to-integrate-razorpay-in-android

https://razorpay.com/docs/payments/payment-gateway/android-integration/standard/#sample-code

Follow these steps to integrate your Android application with Razorpay Android Standard SDK:

1.1 Install Razorpay Android Standard SDK.

1.2 Initialize Razorpay Android Standard SDK.

1.3 Create an Order in Server.

1.4 Initiate Payment and Display Checkout Form.

1.5 Handle Success and Error Events.

1.6 Store Fields in Server.

1.7 Verify Payment Signature.

1.8 Verify Payment Status. 

https://github.com/razorpay/razorpay-android-sample-app/blob/master/app/src/main/java/com/razorpay/sampleapp/java/PaymentActivity.java

https://developer.android.com/google/play/billing/integrate#kotlin