Please follow these instructions to setup single sing-on integration for your Xenforo. We don't cover Xenforo integration in details as this information could be found on their official website.
- Install xenForo on the same domain where you have Subrion CMS installed.
- Install xenForo API: https://xenforo.com/community/resources/xenapi-xenforo-rest-api.902/
- Configure Subrion CMS plugins/xenforo/includes/classes/ia.common.xenforo.php file head section constants
- Put absolute URL to forums API URL in config section of Subrion CMS