chipolo makes a credit card shaped tag that works on the find my network, I don't think it has precise location though. (it will update location though find my, and does have a speaker to make sound)
It's a little thicker than 3 standard cards, so it should fit in most any wallet, but you'll need to make sure you still have room for any other cards you want.
you want the "spot" version, the regular card does not work on find my.
(for comparison, an AirTag is about 10 1/2 cards thick, so the chipalo card is much thinner)