Use these instructions if you are already using another app that supports TOTP (e.g. KeePassX or Proton Pass).

1. Open outlook.office.com.
2. Enter your username and password.

1. Click on the I want to use a different authenticator app button.

1. Scan the QR code or click on The image is not scanned?. The second option will send you a secret key to your authenticator app, which you must copy.

Your chosen authenticator app will now be used for the one-time passwords.

If Microsoft still requires your phone number, click on the Skip setup button.