Open Account, Security.

1. Press Set up an authenticator app.
2. Scan the QR code with an app such as Google Authenticator, Microsoft Authenticator or 1Password.
3. Type the six-digit code the app shows.
4. Save the ten backup codes somewhere safe. Each works once if you lose your phone.

From then on, signing in asks for your password and a code from the app.

For your team

The owner sees who is protected, can require two-step sign-in for everyone, and can reset it for someone who has lost their phone.

Without an authenticator app, signing in still has a second step: a one-time code sent to your email.