Hanging Mirror - Confusing Instructions

I bought this mirror from home goods. It’s pretty heavy. The instructions for gypsum wallboard (which is I think what we have - we have drywall) say to use 2 anchors. I’m not a handy person, but the back of this mirror doesn’t seem to have anywhere for two screws to anchor into… it only has the one zig zag hanging hook at the top… and I think this mirror is definitely too heavy to hang on one hook. Am I just dumb and missing something? Or is this just a cheap mirror that wasn’t made right