Summary

This is a push pin that has a hollow base in order to fit a 6 mm diameter x 3 mm height magnet. I made the magnet completely covered on both sides so that the magnet can't slip out while using it. All you have to do while making it is pause the print right before the hollow space is going to be filled so that you can place the magnet inside and then continue the print. These aren't the strongest push pins since the magnets aren't that big but they are strong enough to hold papers on fridges or whiteboards.

These are the magnets I used: https://a.co/d/3e1GsM2