Ensure you’re on the latest firmware here: firmware
How to set xyz zero with a laser on the Onefinity CNC.
M3 turns the laser on
SXXX is the laser power (zeroing will be a value between 1 and 1000)
M5 turns the laser off.
You want to find the lowest S value that fires your laser (not all lasers will have the same number) but does not burn the wood for zeroing.