[makeitdouble]

I had the impression that Apple stores and syncs them for you, but at no point will give you the option to actually backup or restore (have a copy of the info under your management). Let's say I need to move a credential from my account to my wife's, I guess it's probably not allowed. Or god forbid I change Apple IDs.

[brookst]

https://developers.google.com/identity/passkeys/faq#how_can_...

[weikju]

You can export your password (from Safari or from the Settings app) to a csv file. Not sure how that handles passkeys, if at all, however. Probably not (yet).