How do my users reply to a support ticket?

Hello,

When my users create a new support ticket, and after I reply they are sent an email notification with a link to view a response. (copied below)

However when they click the link it just goes to a white page. This is setup on the main site, and the user has been added but I suspect with that url (below) they need to have admin access to view?

Ticket response notification email:

*** DO NOT REPLY TO THIS EMAIL ***

Subject: help please
Status: New
Priority: Critical

Please log into your site and visit the support page to reply to this ticket, if needed.

Visit: http://bluedognetwork.info/wp-admin/admin.php?tid=2&page=ticket-manager&action=edit