Facebook Login aka pk_faceboklogin TYPO3 9 LTS extension by Pavel Kruglov

Such things implemented:
- implemented the final tests of the extension on my web server; 
- added comments to Login class of the extension and all the other scripts;
- added and configured the Facebook Application "Facebool Login" for your domain - info.hightechbgweb.com;
- uploaded the new "Facebook Login" extension to your web server - info.hightechbgweb.com/typo3/;
- created a new usergroup for Front End Users - Info Usergroup;
- created a Folder for Users that contains Website Users wgere the users are stored;
- created new pages on your website for the Facebook Login i.e. "Login" page id = 7 with the Facebook button (https://info.hightechbgweb.com/index.php?id=7), hidden in menu page "FBLogin" where the pk_facebooklogin extension is inserted as a plugin and the user protected page "User Area" with usergroup access;
- added the pk_facebooklogin plugin to a page as a Content Element with id = 8 
info.hightechbgweb.com/index.php
- configured all the settings in the plugin FlexForms on page with id = 8
- tested the extension functionality on your HTTPS web server;
- createed a documentation with the screenshots

As for the documentation, I placed the documentation text document and screenshots of the Facebook App and plugin settings here:
pk_facebooklogin/Documentation/DOCUMENTATION.MD

Please check the documentation first. Let me know if you need a dicumentation in other format.

Here are details in short

Functionality

Users are logged in as long as there is an email address that matches the Facebook account.
If the user does not exist, a FrontendUser account with definable roles and a random password will automatically be created, as user name the Facebook email address will be used.

After successful authentification, the user will be redirected to a so called "redirect page" configured on the plugin settings with the message:  

"You're new here, welcome
Since we could not find a user account, we have created one for you. Have fun:)"

And a Link "Continue" that leads to a page "User Area" only accessed via existing frontend usergroup "Info Usergroup" - info.hightechbgweb.com/index.php

Please check the provided documentation with the screenshots.
Hope everything is clear. But please let me know if you need any questions.

Best wishes,
Pavel Kruglov