I also have the same question. Could somebody let us know the correct procedure.
I have tried authenticating as an end-user with different combinations of the grant type, access endpoint uri, token uri, client secret, etc but was unsuccessful and also tried authenticating as a service account (because as per google authentication-related doc this is the way our application accesses resources from google). but got stuck in signing off using the private key that I got from a google service account.
Could you please provide the right way to integrate to the Google AI platform?