If your camera icon has a red slash through it, your camera is off. Click the camera icon to turn it on (a pop-up for permissions may appear). The red slash will be removed. Click it again to turn the camera off again.
If your camera icon has a red slash through it, your camera is off. Click the camera icon to turn it on (a pop-up for permissions may appear). The red slash will be removed. Click it again to turn the camera off again.