My old shower holder broke up, so few minutes of measurement + modeling, and here we are.

It is usable for 25mm diameter pipe. You can fully rotate showerhead holder in the angle you want.

You will need:

2x M6 nut (s=10mm)

2x M6 screw preferably with hexagon head (1x 40mm long and 1x 25mm long)

In my print profile, there is sliced a pause at layer 74 (8.80mm) so you can insert one of the nuts there (tight but solid fit).

I suggest printing in PETG for more temperature resistance.