Login alerts and two-factor authentication
Managing your alerts and authentication methods
Get alerts about unrecognised logins to Facebook
How two-factor authentication works on Facebook.
How do I use text messages (SMS) for two-factor authentication on Facebook?
What is Code Generator and how does it work?
Get a security code to log in to Facebook
Using an authentication app for two-factor authentication on Facebook
Set up Facebook login recovery codes
Fix a problem with two-factor authentication
Login alerts showing same device at every login
How do I log out of Facebook on another computer, phone or tablet?
Review recent Facebook logins
When and why to save your device to your Facebook account
I have to enter a security code every time I log in to Facebook.