Each registered client that uses Tickethub to support their clients receives a unique Helpdesk URL. Once logged in, they can view and/or change this URL by clicking on "My Account" and accessing the settings screen. You'll find a field called "Helpdesk name" (which you can change here as well if you like).
Simply copy your "Helpdesk name" and paste it to the end of your Tickethub URL. For example, if your helpdesk name is BobJones, then your helpdesk URL will be: http://mytickethubinstall.com/BobJones (replace mytickethubinstall.com with the URL where you have Tickethub installed)