Servo not showing up in mission planner

Sorry for another servo question but I just can’t figure out where is the problem after hours of reading up documentation and similar topics.

Basically I started to set up the system in MIssion Planner without an RC transmitter. I ran through the accelerator and compass set up fine. Then I calibrate the ‘Radio calibration’ without a transmitter using a joystick only.

So here where I’m stuck, When I move on to servo calibration, I did not see any output(no green bar). The servos did not start to move or make any sound when I connect everything. After some research, I suspect it was I didnt ARM the Heli in mission planner, and I have found maybe I should have some settings in the Full Parameter list(disable arm checks and FS_THR to 0). But with no luck seeing any changes with the servo. Then I started to believe it was the good old mistake of not providing power for the servo rail.

Therefore I measure the voltage for the ESC BEC and servo rail as picture showed (I dont have a multimeter so I guess a low voltage alarm will work the same way), the rail only measured 4.X volt. So I bump up the voltage for my BEC with 6V(it is a hobbywing programmable 40A ESC.

Can anyone help me to see what I did wrong or maybe I’ve missed? Is there any way I can test to see if it is my servo malfunction of another hardware issue?

Thanks alot