@selsoe @Pthorn I got you covered: https://infosec.exchange/@iamkale/109564985971645455
Also passkeys are simply a friendlier name for WebAuthn credentials, it's all the same WebAuthn API and the distinction is moot in the browser. And you can definitely use WebAuthn with Mastodon even if it's in an environment that doesn't support backup of credentials (which is what passkeys are really about, backing up credentials)
@Pthorn I can’t find the option on Mastodon. Maybe it’s only available during sign-up or on certain servers.