To set-up Addon companies on InterWorx you need to make a secondary domain (can probably use another siteworx account instead)
Domains > Secondary > add.
After adding the domain we need to go into the SSH and edit the vhost_sub.domain.com you can do it under: nano /etc/httpd/conf.d/vhost_sub.domain.com.conf
change DocumentRoot url to your Blesta installation root. eg: /home/username/licensecart.com/html/billing/
Restart Apache: service httpd restart
