Getting reverse camera to turn on when in reverse

I bought a joying head unit about a month ago, and finally decided that I wanted a backup cam to go with it. I installed the backup camera (hooked up power to the tail light) and then wired it to the dash. From the limited documentation I could find, I think the orange “BACK” labeled wire on the joying unit should be what I hook the trigger wire up to, so I did that but it still doesn’t open the camera when I go into reverse.

Everything works fine I just have to open the app. I want it to open the camera when I go in reverse. Any tips?

 

Check the camera type input keep switching it and trying in reverse the camera should show I had the same problem

 

I got the camera to work, I just want the app to open automatically when it’s in reverse.