To fit on the mini+ build plate you need to tilt it back and add supports. You shouldn't actually need any supports on the back, but PrusaSlicer likes to add a few random ones.
Aside from that, just print and screw into the wall. It fits into the mounting spots on the shuttle itself.
I've also attached my fusion 360 file in case you want to mess around with it.
The author remixed this model.