Connect to GCP VertexAI for Chat Agent

I am trying to do a very basic call to an LLM via GCP VertexAI. I can’t use Google AI Studio, as that is not an option for my organization, it must be VertexAI.

My service account can connect via Google Authenticator, but I will come back to this. When I connect VertexAI Connector, and set my project id, it fails to connect. I am curious if others have faced this.

It’s also odd that we have to define scope when using a service account when using Google Authenticator, as we itemize the access via the service account already. The only options for Google Authenticator are Analytics, Drive and Sheets.

Can anyone point me to what I might be missing? The service account properly matches the the project id I specified.

I am using version 5.9. Also, when I attempt to use interactive for Google Authenticator, no window pops up.