188
The War on Passwords Is One Step Closer to Being Over
(www.wired.com)
This is a most excellent place for technology news and articles.
Usually just an option in addition to a password + MFA. Or they just replace the MFA option and still require a password. I even saw some variants where it replaced the password but still required a MFA code. It's all over the place. Some providers artificially limit passkeys to certain (usually mobile) platforms.
All of those options are to NIST-spec. MFA means multi-factor. It doesnt matter what they are as long as they are in different categories (something you know, something you have, something you are, etc: password, passkey, auth token, auth app, physical location, the network you are connected to). Two or more of these and you are set (though, location might be a weak factor).