In order for RevenueCat's servers to communicate with Google on your behalf you need to provide a set of service credentials. The process for configuring these credentials is a bit complex, but the added level of control improves security by only providing RevenueCat with the access we need.
Your Play Developer account needs to be linked to a Google Developer Project.
1a. Go to your Play Console settings
Next we need to create a service account. This is done from the Google API Console
When you hit create, a JSON file will be downloaded. These are the credentials that RevenueCat will need to communicate with Google
Set the Role to Project > Owner
Download your JSON credential
Hit save and you're done. Upload the credentials JSON that were downloaded in step 2 to your RevenueCat account and we'll be ready to handle Google Play purchases!
It can take up to 24 hours for your Play Service Credentials to work properly with the Android Developer API. You may see "Invalid Play Store credentials" errors and be unable to make purchases with RevenueCat until this happens.
If this state persists more than 24 hours, contact firstname.lastname@example.org