Custom lock/key?

So for Christmas I am wanting to get my wife/key holder a cuter key she can wear. We currently use a cage with a FYJENNICC internal lock and I would like to keep doing so.

Does anyone know of where to either get a new lock that is compatible with different choices of keys or, where to get copies made from the current key? I checked a few local hardware stores and they can only do house/car keys.

Any ideas?