Actually, I am conducting my classes using Zoom Video Conferencing. I've noticed for awhile that my camera image is flipped like a mirror image. Why this would be the default image for the built-in camera in inexplicable! I didn't really think I needed to do anything about it until I tried to show my student a map of Africa and it was, of course, backwards!
While I could not even find camera controls in either the system or finder preferences, once of my STUDENTS instructed me to check the camera settings in Zoom. Zoom itself had a radio button that allowed me to flip the image correctly. So while the built-in camera is installed "backwards," the online app, unrelated to my Mac, allowed me to correct the manufacturer's error!