For admin to disable it, set:
Code:
active=no
in your:
Code:
/usr/local/directadmin/data/users/admin/ticket.conf
Note that each Reseller has his own toggle, but if you create accounts from Admin, then that's all you'd need to worry about.
You can also set the html text in that file as:
Code:
html=Follow <a href="http://www.domain.com/support">this link</a> for a 3rd party ticket system.