Looking for logging into the Facebook Username Email 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 Facebook Username Email site. After that you can login as usual with your login credentials.
https://www.facebook.com/notes/facebook/log-in-with-your-facebook-username/138003612130/
https://www.facebook.com/help/292105707596942/
https://www.facebook.com/help/community/question/%3Fid%3D10151487935427404
https://www.facebook.com/help/community/question/%3Fid%3D1375824872744630
https://www.youtube.com/watch%3Fv%3Dlk4OJotB6xw
https://www.youtube.com/watch%3Fv%3D68Xw2dfLrj4
https://www.youtube.com/watch%3Fv%3DRwR49vYdhKg
https://www.youtube.com/watch%3Fv%3Dp7K72pV9qAQ
https://www.adweek.com/digital/log-in-to-facebook-with-your-username-instead-of-your-email-address/
https://www.quora.com/How-do-I-find-out-Facebook-users-email-with-Facebook-ID-or-username
https://stackoverflow.com/questions/3611682/facebook-graph-api-how-to-get-users-email
https://smallbusiness.chron.com/change-login-mail-id-facebook-27462.html
https://community.spotify.com/t5/Accounts/How-do-i-find-my-username-when-using-Facebook-login/td-p/859795