Google Analytics Data API

In Google Cloud Console Credentials, create an OAuth 2.0 Client ID for your project, then use Google's OAuth flow to obtain an access token with either the https://www.googleapis.com/auth/analytics.readonly or https://www.googleapis.com/auth/analytics scope for a user who has access to the target Google Analytics property. The Data API quickstart for user credentials shows this setup path.

In Google Cloud Console Service Accounts, create a service account, then grant that service account access to the Google Analytics property. Use the service account credentials to mint a Google OAuth access token with the https://www.googleapis.com/auth/analytics.readonly or https://www.googleapis.com/auth/analytics scope. The Data API quickstart for service accounts documents this path.