Relay output on Pixhawk

Can someone help me with setting up the relay output on a pixhawk. I have to intension to put on a light in front of my hexa+ drone. I have tried at first to use my X8R receiver but it seems that all outputs are PWM and not digital 0 or 1. Then I have setup channel 6 in mission planner controlled by switch SA. Switch 3 has 3 positions and my value in mission planner (page radio calibration) goes from 860 to 2006 so that part is working. Then I have setup CH6 as relay on/off in the extended tuning page. After that I have changed, in the standard parameter list, the first relay pin to Pixhawk FMU AUX1 and second relaypin to FMU AUX2. Finally I changed in the full parameter list, the relay pin to 54 and Relay_pin2 to 55. Still this is not working. Can someone help me? I even have no voltage between ground and voltage on the aux channels. I have a pixhawk 2.4.8. Thanks in advance for your help. Peter Belgium