Sending commands with companion computer to pixhawk

Hi,

These 4 variables are used in the vehicle_command UORB message: target_system, target_component, source_system and source_component number. I would like to know how can I find the number of each of these variables in my system. Considering that I have a pixhawk v5 and a companion computer. Any ideas @LorenzMeier .

Thanks,

MrPotato