Joystick calibration is highly experimental and may not yield the results you actually want anyway.
usage: joycal /dev/input/eventX [options]
options:
--duration N movement capture seconds (default 5)
--noise N centre noise capture seconds (default 2)
--margin F margin fraction (default 0.02)
--deadzone-pad N add padding to computed deadzone (default 8)
--axes CSV only these ABS codes (e.g. 0,1,3,4)
--include-hats include ABS_HAT* axes (default off)
--json output JSON (default on)
--out PATH write JSON to PATH instead of stdout
--print-commands print evdev-joystick example lines
-h, --help show this help
You’ll want to export it to a JSON file at /opt/muos/share/conf/joycal.json once you’ve figured out what values you want to use.