Hi, I'm glad you came to this forum for help! I believe you have the right idea in searching for the fuses. Below are some pictures you may find useful. There is a dedicated fuse box for the electrical equipment inside to the left of the brake pedal.
Pull off the plastic cover and you should see a bunch of little fuses in there. Your car's electrical system might be bypassing the rear view camera entirely even when you switch into reverse because the fuse FOR that camera may have blown. Compare each fuse to the diagram provided in there with the car COMPLETELY off.
I can't seem to get that wire or whatever it is out of the way of my fuse box which is blocking access and I'm afraid I might unplug something, so I won't touch it. I hope there isn't anything in the way of yours.
I also can't figure out which one is specifically for the rear view camera, so you can try checking each fuse. Feel free the check the fuse box in the engine bay too!
I have provided the diagram for the fuse box next to the brake pedal. You can find it in the "2016 Scion iA Owners Manual", starting page 463