This insect hotel should be printed with 100% wooden filaments (such as Extrudr wood Filament) only.
If you print it with PLA or other plastics, it will potentially kill the wild bee larvae!!!

Plastic Filament will lead to a humid environment and the resulting mold can kill the larvae.
Printing with 100% wood Filament also prevents environmental damage through (Micro-)plastics.

I personally only used the Extrudr Wood Filament but other brands with similar composition should also work.
Set it to 0.2mm Resolution and use a 0.6mm Nozzle to avoid clogging (it should work with 0.4mm too but clogging might occur more often).

Also print it in the position as shown in the preview, otherwise the individual holes might come out off.

Usually you will need 10-12 hours printing those.
Best thing is: If you use the Extrudr Wood Filament it's completely compostable.

This thing absolutely works! Put it onto sunny sides, with easy access to all the friendly animals and within a few days, the first insects should show interest.