Basically the procedure is like this:- Download the plugin (www.osticket.com/download)- Copy the plugin to the folder include/plugins- Make sure to set the correct permissions on the plugin phar- Under Admin Panel -> Manage -> Plugins add the new plugin, configure it and finally enable it.If this does not work, please see make sure your web server supports phar files, SE_Linux and other possible error sources are disabled and your php error log does not contain any error.