Request - Step by Step walkthrough to setup Cloud Backup on Google Cloud Storage

Still getting 404s when trying to verify OAuth2 token. Must be missing some setup detail, but I must say that after upgrading to “pro” Virtualmin, the docs on setting up such an important aspect of a server are basically non-existent. Pretty disappointing really. I love Webmin/Virtualmin otherwise.

Can someone please do a visual walkthrough on how to set this up properly?