How to Trigger Camera SJ6 Legend PIxhawk for Mission flight

Hi experts, do you have any idea how can i trigger the camera of my SJ6 Legend during Mission Flight? DO i need to set up things on the QGroundControl? I have this Cable that has, yellow, red, white and black White for the PWM and yellow for AV Cable.

Tried setting the Camera to take photo on mission flight but nothing happens, I didnt set up anything on the parameter. I just connected the White, black and red to AUX 1 on the pixhawk.

Also, i only ave 6CH receiver. Thank you.