Waiting Room
As a moderator, you can decide whether to enable a waiting room when creating a meeting. All participants except moderators will first enter this waiting room when they join the meeting and must be admitted by users with moderation rights.
Waiting Room Settings
You can also change this setting later when editing the meeting.
When you join the meeting as a participant, after the usual name prompt, you will see an additional screen:
Waiting Room Screen
Here, you have the option to deselect Automatically enter meeting without confirmation if you want to confirm your entry manually.
As a moderator, you can see the number of participants in the waiting room displayed in the top right corner.
Number of Participants
By clicking on the icon with the number, you can either approve all participants currently waiting or admit individual participants.

Admitting participants to the meeting.
A moderator can also disable the waiting room during the meeting via the three-dot menu.

Disabling the waiting room.