To make it work you'll need an account with Twilio.
Once created, navigate to Twilio console and copy Phone Number and Account SID into TeamDesk variables. Also, set up 3rd-party account by copying Account SID into username and Auth Token into password fields.
Then you'll be ready to send messages.
You can find detailed description of what's inside in the blog article.
Any support materials, such as spreadsheets and real-life work samples would be very helpful as they would help us better understand your business process.