I was working with WordPress site and my client want me to install PHPBB3 forum for their site. Major requirement is to make a common login for WordPress and PHPBB3. I have searched WordPress plugin for it and found “PHPBB Single Sign On” WordPress plugin. This plugin connects WordPress and PHPBB3 with authentication.
Once you install this plugin and follow the procedure to complete the installation successfully than it will automatically synchronize WordPress and PHPBB3. So your WordPress user can login into forum using the same credentials and PHPBB3 users can login into WordPress with forum’s login details.
You may face some issue during the installation process. You can comment below if you have any question or issue, i will try to answer them as soon as possible.