You can provide a second number for a fallback device. If you lose access to both your primary device and your recovery codes, a backup SMS number can get you back in to your account.
You can use a fallback number regardless of whether you've configured authentication via text message or TOTP mobile application.
Warning: Using a fallback number method is a last resort. SMS messages are only supported for certain countries outside the US; for the list, see "Countries where SMS authentication is supported". For this reason, you should download and safely store your recovery codes. For more information, see "Downloading your two-factor authentication recovery codes."
- In the upper-right corner of any page, click your profile photo, then click Settings.
In the user settings sidebar, click Security.
Next to "Fallback SMS number", click Add.
Under "Fallback SMS number", click Add fallback SMS number.
- Select your country code and type your mobile phone number, including the area code. When your information is correct, click Set fallback.
After setup, the backup device will receive a confirmation SMS.