In a note posted on their site earlier today, Facebook has announced they have updated their two-factor authentication process. The updated version will no longer require you to provide a phone number and will instead accept your accounts on third-party authentication apps such as Google Authenticator and Duo Security on desktop and mobile.
Facebook further emphasized the need for the account security, saying “Two-factor authentication is an industry best practice for providing additional account security. We continue to encourage enabling two-factor authentication to add an extra layer of protection to your Facebook account.”
To set up the new authentication process, go to Settings and head to “Security and Login.” A video detailing the changes can be viewed here.