This website has a list of sites allegedly supporting passkeys: https://passkeys.directory

I say "allegedly", because a few of them (Paypal, eBay, a couple others) have never once offered to let me use a passkey.

Sites I know, off the top of my head (because I used them in the past 24 hours):

* Porkbun

* Google

* GitHub (if you enable the preview feature)

I know I've used more, but I don't have an easy way of searching for them.

thanks, do have an account at a couple listed there so might have to give it a try on an unimportant one

eBay and Paypal do, though I don't know how to get it to prompt you to configure a passkey...

PayPal only started offering it two weeks so so that's probably why. Ebay I don't know, haven't used that in many years