Setting relay pin AUX

please help
on a pixhawk 2.1 with ardupilot and Rover 3.5 I want to set on AUX6 a relay to be controlled from the RC6 remote control and from MP
It seems that I succeeded but you don’t understand why on AUX 6 I only have 1.62 V and not 3.3 V when the lever is operated and 0V when it is not operated