I too have the same problem after looking at old resolutions in other threads.
I hope the "new member"@Anatol is wrong and there will be an answer, support or tuto to solve this problem.
I downloaded version 1.9.1 on github and activated it on a joomla 3.9.27
I also hope that a version will exist for joomla 4, otherwise I give up too!
Of course a reasonable price for a support does not pose a problem for me even if it is for non-profit associations
The problem is that part of the code was removed from the Facebook plugin
Because of what your site does not ask for an email address from Facebook
I solved the problem by adding some of the code to \plugins\slogin_auth\facebook\facebook.php
= implode(, );
= . ;
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