There's nothing special RPs have to do in order to support Passkeys. It's just WebAuthn that happens to be synced. If the site supports WebAuthn it already supp

There's nothing special RPs have to do in order to support Passkeys. It's just WebAuthn that happens to be synced. If the site supports WebAuthn it already supports Passkeys (As long as they're not doing significantly less common things like checking for attestation, which Passkey-enabled credentials won't do).