I have a MacBook Pro from 2015 with a built-in Facetime HD camera. I connect a larger Apple display via Mini DisplayPort on my MacBook. The monitor changes fine, but I want to use the camera on the external monitor so I can keep the MacBook lid closed. The MacBook recognizes only the built-in camera and not the camera built into the external monitor. How can I make the MacBook see and switch to the camera on the external monitor?