The free proxy is a kind of virtual pipe and your traffic flows through it to the destination server (website). That's why the destination server doesn't see your real IP address. In the same time your Internet service provider sees the connection to the free proxy service, not to the destination website. The method FB.api will stop working when called from http I get the next warnings in console. I think it's because we'll need to update the Facebook API. index.js:2178 The method FB.getLoginStatus will stop working when called from http pages in 24 days. Please update your site to use https for 4 Ways to Unblock Facebook - wikiHow Mar 29, 2019 Facebook external login setup in ASP.NET Core | Microsoft Docs
For example, if you buy a regular proxy package, with simple private or shared IPs, you don’t have any guarantee they will connect and login your accounts. Furthermore, these regular IPs might have been used previously on Facebook and they could be already flagged and banned.
Log into Facebook to start sharing and connecting with your friends, family, and people you know.
4 Ways to Unblock Facebook - wikiHow Mar 29, 2019 Facebook external login setup in ASP.NET Core | Microsoft Docs