Now you need to tell VSys all about your Twilio account.
From the Setup panel, click on the SMS/text message settings link, or from within the SMS/text message manager, click on the Settings link.
Enter your User ID (should begin with "AC") and Password.
Click in (add) to add at least one incoming phone number. (This is a phone number that you've acquired from Twilio.)
Enter the phone number, an optional description, and choose the type of incoming message that this phone number represents. (Messages which are texted to this phone number become incoming messages of this type.)