To enable it for your Facebook account: Many websites allow users to log into their sites and apps via their existing Facebook accounts. If you have done that earlier and no longer use that ...

If you have used another computer or mobile device to sign into Facebook frequently, try logging into your account using that device. See if Facebook recognizes your device or not. If it does ...

You can log into Facebook on your computer or phone using the website or app. Once you've logged into Facebook, you can save your account information and log in ...