Why do I need to login to my Google Account after I click on the meeting URL?

The meeting was scheduled by using our add-on Attendance Taker for Classroom.

You are required to sign in with your Google account which is associated with Google Classroom, and your attendance will be taken automatically.

If you keep your Google account signed in, you will not be asked to sign in. You can also use the one-tap login if you have signed in to your Google account previously.