Reset Firefox Permissions

What to do if you didn't allow camera or mic access

If access to the device’s camera and mic was accidentally denied then it is required to reset the browser permissions.

Open the menu and go to Preferences or Options.
Scroll down to Privacy & Security.
Go to Cookies & Site Data.
Select Clear Data.
Return to the Dashboard or the waiting room and refresh the page.
The user will be asked to allow access to the camera and mic and then Allow should be selected.