Facebook uses a security measure called Login Approvals that sends a verification code to your mobile phone each time you use a different computer or device to access your Facebook account.

Mac 911 How to add your verification codes to Apple Passwords Apple added support for a form of two-factor verification code in iOS/iPadOS 15 and Safari 15 for macOS.

You'll be taken to Settings -> Passwords, where you may need to manually select the correct account to add the verification code.

The use of verification codes is known as two-factor authentication (2FA). 2FA offers hardened security during login attempts by requesting that the user provides an extra piece of information ...