If they started laying about a month after you provided the extra light, that is about what I would expect if the light made the difference.
It takes several weeks for a hen's body to go from not-laying to laying. She grows a whole bunch of egg yolks from pinhead-size up to ready-to-lay yolk size, and then every day or two she can put the egg white & shell on one egg and lay it.
We are into the time of year (in the northern hemisphere) when the days are getting longer, and many pullets and hens are starting to lay again. Some do it sooner than others. But because some of them are naturally starting to lay again, people find many kinds of "tricks" that do not really work-- the person just happened to try it when the hens were about ready to lay anyway, so it looks like it worked.
ANY trick, tip, or idea that seems to cause laying in less than a week or two, is not really bringing the hens from a state of completely not-laying to a state of laying eggs. Something that actually causes laying should take around a month to work, plus or minus a bit because not all hens are alike. (Sort-of exception: if hens are already laying but are hiding the eggs or eating them, anything that makes them stop those behaviors can work quickly, because the eggs are being laid anyway. It's just a matter of the person being able to get them. But that is not really the same thing as making a non-layer start laying again.)