How do I install track for sliding closet door on laminate
Laminate flooring is made to move when needed, so screwing through to the subfloor under the laminate may not do the floor well. Since sliding doors do not exert a lot of pressure at the guides on the bottom, you could size the screw to only secure itself into the laminate itself, say no more than 1/2" long screws, considering the laminate should be about 3/8" thick, the mounting plate is about 1/16" thick and the pad under the flooring adds a little too. If the laminate flooring is 1/2" thick, like some are, then a 5/8" screw could be used. Using screws this small should be run in manually, not with a power tool.

To be sure everything moves as it should, you could set the guide completely then remove the screws, file just the sharp point of the screw off, about 1/16", then reset the screws.

Although the floor does move a bit, it should not affect the operation of the guide. If the floor does move enough to do so, more than a 1/2", then you have other issues to worry about.