Looking for logging into the Phpbb3 For Other Services 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 Phpbb3 For Other Services site. After that you can login as usual with your login credentials.
https://area51.phpbb.com/docs/dev/3.2.x/extensions/tutorial_authentication.html
https://www.phpbb.com/community/viewtopic.php?t=2264796
https://www.siteground.com/phpbb-security.htm
https://stackoverflow.com/questions/42844856/how-to-use-phpbb-login-in-a-webpage-outside-the-forum
https://allianceauth.readthedocs.io/en/v2.0b3/installation/services/phpbb3/
https://docs.oneall.com/plugins/guide/social-login-phpbb/3.1/
https://www.youtube.com/watch?v=Jq4csat4jNU
https://wiki.univention.de/index.php/Cool_Solution_-_Setting_up_phpBB3_with_LDAP_authentication
https://github.com/oneall/social-login-phpbb
https://www.interserver.net/tips/kb/enable-ssl-phpbb/
https://www.phpbbservices.com/
https://www.mediawiki.org/wiki/Extension:Phpbb_Single_Sign-On
http://doc.tiki.org/phpBB-Authentication