Passkeys — Face ID, Touch ID, Windows Hello, or a security key — are tied to the specific device that created them. If that device is lost, replaced, or reset, the passkey doesn't travel with you automatically.

If the device your passkey lived on is gone, fall back to your email address: request a magic link or a sign-in code (see Sign-in options). Your account still exists and your email address still works, even though the passkey does not.

Once you're signed in on your new device, go to Settings → Security and remove the stale passkey entry for the device you lost. Leaving it there is harmless — a lost device can't use it without also having your device's own unlock (fingerprint, face, or PIN) — but removing it keeps your account's credential list accurate.

From the same Settings → Security page, you can register a new passkey on your current device so you can sign in with Face ID, Touch ID, or Windows Hello going forward, without needing an email each time.