Sign in with Google button is missing

When you go to the login URL for your website, do you see only the "Sign in as Super Administrator" option?

If so, your school is using Google single sign on (Google SSO) and the login button is being hidden by an ad blocker. Some ad blockers hide non-ad elements.

Disable the ad blocker or whitelist the URL to solve this.

Then refresh the page to see the Sign in with Google button.