Looking for logging into the Joomla Admin Loop 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 Joomla Admin Loop site. After that you can login as usual with your login credentials.
https://forum.joomla.org/viewtopic.php?t=951232
https://www.itoctopus.com/yet-another-login-loop-in-joomlas-backend
https://rockettheme.com/forum/general-discussion/189802-solved-joomla-admin-loops
https://stackoverflow.com/questions/18278255/how-to-make-my-joomla-admin-login-page-working
https://quantumwarp.com/kb/articles/30-joomla/316-joomla-admin-login-loop-cannot-login
http://www.pwrusr.com/web/cannot-login-to-joomla-backend-as-admin
https://github.com/joomla/joomla-cms/issues/22556
https://www.siteground.com/kb/i_cant_log_into_the_joomla_backend_as_administrator/
https://forum.joomla.de/thread/5194-admin-login-nimmt-benutzerdaten-nicht-an/
https://www.joomla.ch/forum/81-allgemein/24429-admin-login-loop
https://www.freelancer.pk/work/admin-login-loop-joomla/
http://volke-j.de/joomla-admin-login-loop/
https://www.jms2win.com/en/forum/23-general-questions/11171-admin-login-loop