Preliminary Remarks
The service account created and managed in the Google Cloud Console requires access to the desired app(s). This access is made possible by adding the service account as a user within the Google Play Console.
It is also necessary to link an app to a previously created pub/sub theme.
Enable service account access to apps
Open and log in to the Google Play Console
Click on the "Invite new user" button in the main menu
Add the address of the service account to the invitation
The address of a service account has the following structure: {Dienstkontoname}@{projektname}iam.gserviceaccount.comAdd app permissions:
Selection of the app(s) to be accessed by the service account
Click on the "Apply" button
Then at least the "View app information and download bulk reports (read-only)" and "Financial data" authorizations must be activated. The option "View information on app quality (read-only)" is also activated.
Confirm the selection via the "Apply" button
Complete the process by clicking the "Invite user" button
Connect pub/sub theme with app
Select the desired app in the Google Play Console
In the "Monetize" menu area, select the "Monetization setup" item
In the "Google Play Billing" area, enter the name of the Cloud Pub/sub-theme to which the app is to be linked in the "Theme name" field. The topic must be specified in the format projects/{project_id}/topics/{topic_name}
Confirm the connection using the "Save changes" button