Setup voice response on twilio with appscript

[Le pirate noir]

I bought a twilio phone number and i would like to setup a voice response with appscript when someone call that number. 

Here what i tried, but doesn't work

function doGet() {

var t = HtmlService.createHtmlOutputFromFile("twiml")

 var content = t.evaluate().getContent();

  return ContentService.createTextOutput(content).setMimeType(ContentService.MimeType.XML)

}

html

<Response> 

  

  <Gather timeout="3" >

    

  <Say voice="man" language="en-us"> Welcome to John auto parts. 

To leave us a message click on 1

To cancel an appointment, press 2.

  </Say>

        

     </Gather>

  <Say voice="man" language="en-us">We didn't receive any anwers from you. Bye !</Say>

  

</Response>