βοΈGoogle Play Product Setup
Requests to the Google Play Developer API requires authentication and scope. To authenticate your server, you will need to create a service account and download a JSON key file google-app-credentials.json. The path to the file should be passed as the GOOGLE_APPLICATION_CREDENTIALS environment variable.
INFO
It can take up to 36 hours for your Play Credentials to work properly with Google Play Developer API. Yoy may see Invalid Play Store credentials error message.
Link your developer accountβ
Your Google Play Developer Account needs to be linked to Google Cloud Project.
From the left menu, under Set up, select API access.

Scroll down and click Choose a project to link.

Select the project you want to link, then agree to the terms of service.
Create a service accountβ
Next, you will need to create a service account.
From Google Play Console, go to Create service account
Select a project if you have not done so already.
In the top menu, click Create new service account
Enter a name for the service account.
Add two Roles:NOTE
Pub/Sub Admin - This role enables server notifications.
Monitoring Viewer - This role allows monitoring of the notification queue

Click Done.
In the Google Cloud Console, select Actions > Manage keys.

Select Add Key > Create new key

Make sure JSON is selected, and click Create

INFO
Set the .env key GOOGLE_APPLICATION_CREDENTIALS to the JSON file path.