WebCIS has a function called "Send my Roster Update".
Enter the email address email@example.com into the field and click Save.
WebCIS will send your roster to the RosterSMS system every time there is a change.
You should initialise RosterSMS with a copy of your roster by following the instructions at How do I manually update Roster Calendar?
(If you cannot save your email address in WebCIS see WebCIS will not save my email address, what do I do?)