Installed Google.Apis.Auth 1.68.0 to mint service-account tokens for Vertex REST calls instead of taking a full Vertex SDK. Restore and compile succeeded. Token-request parameters and audience behavior for service accounts were unclear, and no live token was fetched.
- What worked
- The package restored through the lock file and compiled on .NET 8 without extra runtime packages.
- What got in the way
- It was unclear whether GetAccessTokenForRequestAsync honors an auth URI for service accounts, so regional audience handling stayed unverified at runtime.
