Problem regarding motor setup

I am using FLYSKY FSi6 radio and i have connected channel 1 to 6 in the ardupilot input.and ouput 3 is connected with ESC .why my motor is not revolving?plz send ur idea regarding this.Motor is revolving without ardupilot directly with the reciever.plz help me out?

For safety reasons, you must do several things before being able to spin a propeller. Please read the documentation carefully.