You need an empty insert found here: https://www.printables.com/model/152592-honeycomb-storage-wall/files to mount this holder.
Orient as shown in the picture, and slice however you like!
(PLA, 3 perimeters, and 0.2mm layers worked for me)
The holder intentionally fits quite tightly in inserts.
The author remixed this model.
Removed hexagonal holes to speed up printing and increase strength.
(Exact dimensions might be different, as I basically made a new design with inspiration from the original)