There are some great toilet paper holders out there that screw to the wall, but my wall is tile, and I didn't want to make holes in it.
I created this to slide on to the bottom shelf of my organizer. The fit was pretty good, but a piece of double-sided tape on the back bottom edge could be useful to secure it from sliding around.
There are 2 models with different gaps sizes. The bottom wood thickness is 1/2 inch, so I made the gap 13.5 mm to give a bit of space. I had another similar organizer that used 5/8 inch, so a separate model was made with 16.4mm gap.
These were printed in PLA with no supports. I usually print in Voron part spec 5 tops/bottoms, and 4 walls, and 40% infill. I don't think this is necessary, but your experience may vary,
The author marked this model as their own original creation.