Shelf for IKEA Bamboo RÅGRUND toilet roll holder

I purchased a IKEA Bamboo RÅGRUND toilet roll holder ages ago, love the product but If you with your phone in the toilet I don't have anyplace to place it. So I designed a piece that I can use this toilet roll holder on top of it.

Printed with PLA,  attached 3mf file for profile and printing orientation. The step file added as well so feel free to modify.

Cheers!