How do I fix insufficient permissions errors when verifying purchase subscriptions using the Google Play Developer API on Heroku?

Steps to Resolve Permissions Issues with the Google Play Developer API

1. Use a Service Account:

   • Instead of relying on a user account (even if it’s an Administrator), create a dedicated Google Cloud service account.
   • This service account should be specifically linked and authorized for accessing the Play Developer API.

2. Link the Service Account in Your Play Console:

   • In the Google Play Console, go to Settings > API Access.
   • Link the service account’s email to your developer account by adding it as a user with the required permissions.
   • Ensure that the service account has the necessary roles (often "View financial data" and/or "Manage orders" if required).

3. Verify API Enablement and Credentials:

   • Double-check that the Google Play Developer API is enabled for your Google Cloud project that hosts the service account.
   • Ensure that your backend is using the correct credentials file (JSON key) associated with this service account for its OAuth operations.

4. Adjust OAuth Scopes if Needed:

   • Confirm that the OAuth scopes in your verification request include the required scope for accessing purchase and subscription data.

5. Testing Environment Considerations:

   • When using test subscriptions, ensure that you’re running in the correct environment (sandbox vs. production). Sometimes test purchases need their own configuration in the Play Developer Console.

By following these steps, you ensure that your backend service is properly authenticated with an account that has the explicit permissions to verify subscriptions via the Google Play Developer API.

If the issue persists after taking these steps, consider double-checking the API documentation for any additional access requirements or potential changes in the role assignments.