Trying to setup chdk camera control

I have a camera setup with chdk and have made a connector with a E-flite led controller that will trigger the camera with a switch when the cable is plugged directly into the rx. I can’t get it to work with the apm.

I have it on pin A7. (#8 pin from the telem port since there is a 0 pin)
Camera gimbal page shutter trigger is set to chan 7.
Chan 7 opt is set at 9 for camera trigger.
RC 7 function is set at 10 for camera trigger.

When i flip the switch with these settings nothing happens, but when I unplug the cable from the APM it takes a picture.