How do I switch on two-step sign-in?

1. Install an authenticator app (for example Google Authenticator or Microsoft Authenticator).
2. Go to My account → Two-step sign-in and scan the code with the app.
3. Type the 6-digit code the app shows and save.
4. Keep the recovery codes somewhere safe.

Lost your phone? Use a recovery code to sign in, then make new codes.