Servo on RC Channel

ArduCopter
,
1

How can I control the servo motor, by changing the switch of my radio transmitter?

I have gone through this documentation Servo — Copter documentation (ardupilot.org). According to this I have connected my servo motor on AUX 1. What setting should I do on the mission planner, so when I press a button on a receiver (eg, CH 9)

2

and is it necessary to use bec/esc to control the servo ?

3

Never mind I watched this [ArduPilot] 픽스호크 서보 모터 세팅 Servo motor setting (youtube.com).
But do I need to connect my BEC with servo also, or only connect it with the pixhawk AUX OUT 6 ?