Does the same you can do manually as explained here:
Thoughts on optimizing gain - #2 by wiedehopf
There are adjustable amplifiers inside the stick, that’s what you adjust when adjusting gain.
In short it turns the volume knob until it’s not too loud and not too quiet.
That’s approximated by the number of messages louder than -3dB.
0 dB is very loud, -40 dB is very quiet.