Connect Servo to Pixhawk, please help

Hello, I have such environment:

  • Pixhawk Orange Cube
  • Qgroundcontrol App
  • MX16 Series All-in-one Portable Ground Control Station
  1. I connected dc/dc converter to AUX6 with 5.5 V
  2. I connected analog servo to AUX4
  3. In Qgroundcontrol I changed RC_MAP_AUX4 to channel 8

Then I turn power on I am hearing signs of life on the servo, but it does not respond to channel switching on the remote control.

Could you, please, assist me with this servo to Pixhawk connection?