I've printed this in PLA, and the cap grips the knife well. I have an Ender 3 v2, so depending on your printer, you might want to scale the model in your slicer. Designed to print without supports.

The cap is designed to be safe, so the blade doesn't reach far enough to cut into the plastic walls, also you can't put your fingers in the hole of the “stand” part of the cap. The hole is there so this can be printed without supports, which would be a pain to remove.