On fairmeeting.net without logging in, everyone is a moderator. This is indicated by a crown icon.
Moderators can use the three-dot menu next to someone (or all other participants) to disable the camera or microphone (for example, if there is background noise).
With a login (pro.fairmeeting.net), the person who opens the room is initially the moderator. They can then also use the three-dot menu to make other people co-moderators.
If you need even more options as a moderator, we recommend fairteaching - there you can set exactly what users are and are not permitted to do in the room.