If you want to protect your room from unwanted participants, you can lock the room and the participants need your permission to join the meeting. Here is the steps of how to lock the room.
2. Click the Participants icon on the bottom of the screen and then right click the participant's name, you will see the "Lock Meeting" option below:
3. When a participant tries to join your meeting from a computer, it will show Waiting for the host’s approval as below:
When joining from a mobile device, it shows Waiting For Approval as below:
4. On the host’s end, it shows a list of applicants, and you can accept or reject them to join.