Google Pay Prerequisite

Step 1: Check Google Pay brand guidelines on your app.

Reference: brand guidelines

Step 2: About the test environment.

Reference: integration checklist

Step 3: Request production access.

Reference: request production access

1. Click on Google Pay API menu and manage the app.
   

1. Select integration type as "Gateway" and upload screenshoot of your app. Lastly, submit for approval.
   Reference: brand guidelines
   
2. Start to proceed Google Pay once your app approved. Please make sure your integration type are "Gateway".
   

Step 4: Make sure your app are signed with release key and using production environment.

Reference: deploy your application

Step 5(Optional): Join Google Pay test card suite group.

Reference: test suite group