The model can be printed upright. The neat thing is, it already includes supports - no need to make your slicer create your own. The supports will come off the model very easily - they might even fall off on their own when you peel the finished print off the print bed.
The alignment pegs are designed to not require support. They will print just fine without them.
Additionally, you will need two of the M2.5 Skadis T-Nuts by @6d6178 and two M2.5 DIN912 (or equivalent) screw for mounting the holder.
The author marked this model as their own original creation.