As a speaker, you have the option to manage attendees during your session. At any point you may wish to mute or allow audio, for example.
By default, any attendee in the session can share their video, screen, and audio.
In the session view, you will find three buttons at the bottom of the page; Mute Participants, Turn Off Participants' Videos, and End Session.
Mute participants: this will turn off audio for all attendees.
Turn off participants videos: this will stop all attendees from sharing their videos.
End session: when you're ready to finish, your can click on end session. This will end the video, but attendees will continue being able to use the chat.