The Barbie Magnet has inserts for 3x 6x3mm Magnets.
There is an optional counter plate so you can wear it as a badge on your costume, without destroying it.

The inserts for the Magnets are press-fit.
Use a hammer to get them in.

Ken Magnet:
https://makerworld.com/en/models/169165

Doctor Barbie Badge:
https://makerworld.com/en/models/174450