Add CHMSL with camera

[deeretech]

Wife just bought a 2019 2500 with 8.4 screen with Nav. I was hoping to add the 3rd brake light with camera for hooking gooseneck up easier. I was able to do it in my 2013 by adding a camera input but wanted to see if this 2019 might already have the wiring in place for oem camera even though its not there. Also is there any other open camera feeds into the system? It does not have the surround view system. I have a camera on the back of our stock trailer that she would very much like to work lol