If you have a diode laser, and need to turn it on at low power to focus it, LightBurn has a setting for this. First, in Edit -> Device Settings, click the “Enable Laser Fire Button” shown here in the lower right:
Then quit, and restart LightBurn. In the Move window, you’ll find the Fire button and the power setting at the lower right:
Set the power just high enough for you to see the laser when you enable the Fire button. Note that this is a toggle - the laser will stay on until you turn the button off again, or if you position the laser (this is a safety measure).
If you want the laser to be visible when framing a job, once you have the “Fire” button enabled and have a power value entered, holding the Shift key when you click one of the “Frame” buttons will turn on the laser at the specified power level while running the frame.
Please note - this is for diode lasers only, and very, dangerous for CO2 machines.