As already said, not all boards have it. If you load the Grbl 1.1c firmware (or 0.9g) and the laser is always on then you need to move the jumper. The other way to check is look and see what laser pin you have selected in Benbox, if it's 11 then you are already setup on >=0.9 but if it says 12 then you are on the older setting <=0.8.