I may be the only person who has had a problem with this, but I needed a hard-to-remove doorstop to keep little hands from getting smooshed. Regular doorstops just got absconded with, carried around and lost. The worst door of all was the swinging door between the kitchen and dining room. Very fun for the tiny people to push and make swing closed. Also very heavy and finger-endangering. I finally figured out a solution that works. It’s very easy, doesn’t involve drilling holes, and uses things I had laying around.
Take two cylindrical blocks from the toy box or segments of doweling about 1 1/4-inch in diameter or larger. Wrap two big rubber bands like the ones used to package broccoli around each block. Wrap a fifth rubber band around both blocks together.
It may be that you need larger blocks, more or thicker rubber bands, or to twist the rubber bands to give them more traction. The rubber bands may need replacing periodically if they get dried out. Experiment with what works for your door.