I wanted to use it as a countertop compost can but was annoyed by the bag being visible on the outside, and how often the bag would fall in.
The larger bins in the system all come with plastic rings to keep the bag inside, and I can't say why they didn't include one for this!
It's fairly intuitive to use, just place the bag through the hole, fold the bag over the rim, and place in the bin.
I printed using Beige Prusamint PLA @ 15% infill and 3 perimeters but do what you feel.
The author hasn't provided the model origin yet.