Being 15" wide, it's probable that it will sit over a stud (16" on center). Screw through the back into the stud in several places.

The metal strips sound like a manufactured version of a French cleat. You are only going to hit at most one stud, so you will need some other sort of arrangement such as a molly for the one(s) that miss studs.

I've hung cabinets similar to that by centering the cabinet on a stud and using screws in the top and bottom mounting strips of the cabinet.

The location where I'm hoping to hang the cupboard is a small area and I might not find a stud there. I guess I'll just use the toggle bolts again. Last time I had such a time hanging it because I had to prop the cupboard up with on a ladder to keep it in place while working. Any tips on how to do that?