Most apps that use the Mac camera come with their own configuration options, so there’s no on-and-off switch - neither physical nor software.
But don’t rush to assume that now you need to somehow “connect” the camera back on or that there’s a hardware issue that requires warranty service: The “There is no connected camera” error might surprise you anytime with any app if it finds your camera not working on MacBook. When you have your MacBook camera not working properly, it’ll say disconnected or unavailable. Possible Reasons For Webcam Not Working On Mac
