How to join a Google Classroom meeting from a link or code on any device

Students can join a Google Classroom via an email code they received, a class link, or a specially assigned class code.

How to use the new 'Companion mode' feature in Google Meet to join meetings with a second screen

Companion mode in Google Meet lets you join a meeting with a second device that's focused on screen sharing or using a whiteboard.
Android Authority

Google just made Quick Share even better with QR code sharing

Google is rolling out QR code-based sharing for Quick Share. Once another Android device scans your QR code, you can send your files to that device. The feature is available with version 24.49.33 of ...