Teachers can use Google Calendar to build Breakout Rooms in advance. This is different than using your Classroom Google Meet link. Teachers can invite students directly using Calendar. Teachers can turn off quick access to require students to "ask to join" if they are not directly invited to prevent unwanted guests. By teachers creating the Breakout Rooms in advance, they can avoid the awkward fumbling with them during the Google Meet.
Two tips that are not mentioned in the video:
1. On Google Calendar, uncheck the option for guests to invite more guests.
2. End the call completely by clicking the hangup phone instead of closing the tab. Then you'll have the option to end the call completely instead of having an existing Google Meet link running continuously.