Where to get security keys

They may be purchased thru Amazon or directly from the manufacturer’s web store.

DO use care in picking appropriate interfaces (e.g. USB-A, USB-C, NFC, Lightning)

Hi! Apple doesn't sell these, so you will have to purchase a security key from a third-party retailer. :)

Take care!

Glad you thought it out.

They certainly are NOT meant to be for everyone.