I retrofitted a Jackpot controller on a JL1 laser.
The key in LightBurn was to make sure the Enable DTR signal setting was set.
In my setup, I use an enable pin for safety, but most folks wire the laser module enable directly to power.
I think the changes that were settled on for a config with an LR3 and a laser module are shown in the screenshot from Ryan below.
Also, note there is one difference in my screenshot vs the config from Ryan.
You have to have Lightburn and FluidNC set the same for maximum S value. In my screenshot it is set to 1000, in Ryan’s screenshot the speed map maxes out at 255. If you don’t match these up correctly, you’ll either have very low output power or you’ll have only super high output power.