It doesn't have it built in, but you can add it using the "gpu_set_cullmode()" function that Game Maker has. Please keep in mind, however, that this system is for sprite stacking, and doesn't have .obj model support built in, so back-face culling won't be incredibly useful for sprite stacks since they are essentially a stack of 2d planes. This is mostly a quick and dirty 3D solution for beginners, but it should really only be a stepping stone to learning full 3D IMO. :)
If you want to learn more about 3D in Game Maker I cannot recommend Dragonitespam's 3D tutorials enough! They are really well done, and pretty much how I learned to even make this system! haha.
Best of luck! :)