google cloud appengine standard run shield:setup

Hi all, 

I been able to get google cloud appengine working with CI4. 
I have a CI4 instance running, I can talk to a the cloud sql database, I can use the google API to talk to cloud storage. 
My application uses shield for authentication. GCP appengine has no console to SSH into to run shieldetup. 
How would I get this to work? Would I use the scripts directive in the composer.json? How would I answer the questions that are prompted in shieldetup process.

Thank you in advance for your time in responding