To get this working, you need to create an account on Twilio. The trial will give you a phone number and will let you input a new phone number.
In the trial, only the phone number you enter, your own will work for it for calling. This is the phone number you type in the box.
From='+1<Your-twilio-phone-number>' with the number provided by Twilio. So this might
724-867-5309; then the spot becomes
From='+17248675309'. Finally replace the spots for Twilio Account number in two places and Twilio Auth Token in one place.