Shower Door Installation

I am putting in a new shower. It will be a kit with 3 walls and the pan. For the shower door, do I need to put two studs (one for each side)behind where it will go? If not, then will the fiberglass in the walls be secure enough to hold it?

There was no stud with the old shower as the door was secured with an achor that went through the tile and sheetrock.

Thanks

The surround needs to be fastened to studs on the edges. This will put a stud in position for the door to fasten to as well.

Assuming the shower walls are anchored properly, hollow wall anchors into the wall will be plenty to hold the shower door side rails in place. The bottom track normally is not screwed down, but help in place by the side brackets and caulk. the top header normally just sits on the side rails.