Looking for logging into the Fb First site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Fb First site. After that you can login as usual with your login credentials.
https://en-gb.facebook.com/
https://www.facebook.com/help/community/question/?id=233967383478170
https://developers.facebook.com/docs/facebook-login/android/
https://www.facebook.com/help/login
https://stackoverflow.com/questions/34280059/first-time-login-to-the-app-with-facebook-login-will-redirect-to-app-register-p
https://github.com/jeduan/cordova-plugin-facebook4/issues/299
https://blackdesert.zendesk.com/hc/en-us/articles/115000027769-Facebook-Login
https://support.ftgames.com/hc/en-us/community/posts/360003013489-Error-11-Facebook-profile-login
https://support.strava.com/hc/en-us/articles/216942767-How-to-switch-from-a-Facebook-login-to-email-login
https://www.qualtrics.com/community/discussion/1869/facebook-login-javascript-sdk-only-running-in-first-page
https://support.knack.com/hc/en-us/articles/231796207-Single-Sign-On-with-Google-Facebook-Twitter-and-Custom
https://www.shoutmeloud.com/how-to-solve-facebook-login-problem.html
https://customer.real.com/hc/en-us/articles/205522268-Change-login-from-Facebook-account-to-email-address