Back Up Camera Wiring Question

I’m going to be installing a GMA12S-6g in to my 2011 Chevy Silverado soon and was wondering if anyone has been able to wire the back up camera to not only come on when the car is put in to reverse, but to also come on by pressing some kind of button on the screen. The reason would be to be able to turn on the camera briefly while I’m towing a trailer, to check on the trailer connection etc while going down the road.

Would it be possible maybe to use an RCA Y split before it plugs in to the back of the head unit and hook the other RCA cables in to the front camera ports?

Any help would be appreciated.

Thank you