This is a 2 part PLA case printed on Ender 3 v3 SE using Creality's current slicer version. I do not own an Iphone so have not tested it. Let me get some feed back if it works for you or any tweaks you would like to see.

Recommend: Flip the “case cover” face plate down/ dovetails up, with tree supports. Each part takes about an hour of print time. I kept them separate files so you can tweak the filament colors and infill designs. Otherwise, have fun.