If your users are receiving the following error while trying to authenticate into your application with their Google account:

This app is blocked. This app tried to access sensitive info in your Google Account. To keep your account safe, Google blocked this access.

Cause:

If your Google Cloud project is unverified, there is a 100 user OAuth rate limit quota. After 100 Google accounts have been authenticated into your project, more users will be unable to authenticate.

If your users are using G Suite accounts, and the G Suite administrator has whitelisted your application those users will not count towards the 100 user limit.

Resolutions:

• Undergo the Google Verification process for your application.
• Request the accounts mail administrator to whitelist your application.

Warning: If your google APP goes over 100 user over the lifetime of the app they will see the app is blocked warning, there is no reducing this number.