You can join the scheduled classroom using the 'Enrolled Classes' tab from the Learn@Home tab.

The 'Join Now' button will appear before you in Today's Classes section when the staff starts the virtual classroom. You should click the 'Join Now' button to join the virtual classroom meeting.

Once you join the classroom, the status of that particular class will be changed to in-progress from scheduled.

If you got disconnected during the class, you can rejoin the same by clicking the 'Rejoin' button.