Gcp authentication authorization - vidyasekaran/GCP GitHub Wiki
How can I add authentication and identity management to my own app?
Select and enable "Identity Platform" (add google grade identity and access management to your applications and services)
You can add many providers here.
Settings ( can enable and monitor user activity logging)
Identity provider app shows UI which has provision to use signing using SAML / ODC / Github/Email/ google
Go to providers and click on application setup where you have code snippet to be used in our code to be configured. Add this javascript code to index.html
If u choose email as provider once you click login you get the token needed to use this token to backend your get authenticated.