No passkey yet
If your account was made before passkeys, or a skipper created it for you aboard, it may have no passkey on it — and then there is nothing to sign in with. This sends a link that lets you make one.
Back to sign in
This only works on an account with no passkey at all. If yours has one and you
have lost the device, use a recovery code instead — a
link like this can never take an account from somebody who can already sign in.