Joystick to control two servos on channels 7 and 8

Ground Control Software APM Planner 2.0
1

I want to operate two servos on channels 7 and 8 using a joystick. I’m using a Navio2 on Arducopter 3.4.

I set the channels in the complete list of parameters to pass-through (function=1).

I cannot get a servo to move on channels 7 and 8, nor can I see any activity on channels 7 and 8 in the status screen.

What exactly does “Mappings” mean in this screen? Channel 0 seems to be pitch? Or, I just do not understand it.

What is the procedure with APM Planner? Also, how do you assign functions like arm and disarm to the buttons?

Thanks,

Paul
p.s. I can get it to work fine with Mission Planner.