Once that function is published to a URL, you can configure your Twilio numbers so that calls are routed to that function's URL.
Function parameters that share names with the
Twilio request parameters will be automatically provided (the same is true when the handler is receiving a text message).
Positional parameters are handled in order, and the return values are converted into TwilML.
For instance, if you return a string from a function, Twilio will read it with the
Say verb. If that string starts with http, Twilio will Play it with the
Play verb. If the result could be XML, it will return the result inside of the TwilML.