If you lose your passkey, this code is the only other way to open your private pages from a new browser. We don't keep a copy and can't recover it. Put it in your password manager.
Your passkey unlocks your private pages on any browser where it syncs. It doesn't sign you in; your email link still does that.
This passkey can't unlock pages (your password manager doesn't support it yet). You can use your recovery code instead, or try a different passkey manager.
Every browser you sign in to stops being able to open your private pages through your account. Browsers that already opened them, and links that carry a key, keep working.
You'll get a new recovery code and add your passkey again. Your old code and passkeys stop working. Agents connected to this account will ask you to confirm the new fingerprint.