There is a hole to glue a magnet into the soap holder. You'll also need some steel caps to put into the soap bar.
I glued the wall mount to the wall with tesa power strips waterproof. The fit of the dovetail guide is a bit loose so I wrapped thread seal tape/teflon tape around the dovetail to tighten the seat.
Wall mount/dovetail guide inspired by https://www.thingiverse.com/thing:2858010.
The author hasn't provided the model origin yet.