I'm not quite sure what you're asking but if you're asking how to generate a drill/fab drawing, the way I do it is by using an .outjob file. Here, you can set which layers you want to use to generate your fab drawing. There's a bit of a learning curve, and the whole think is pretty clunky and non-intuitive (like much of Altium) but in the end it's probably worth learning how to use outjobs.
The other way to do it is:File/Fabrication Outputs/Drill Drawings
Not sure why you want your Fab drawing to be a Gerber.