Formatting XML for Twilio Response - laravel

Question

I am attempting to receive a fax in my Laravel app, but I can't seem to format the XML properly.
Since I am just setting this up for the first time, I tried to emulate the basic how-to in the Twilio Quickstart guide.
Using the Twilio dashboard, I have set a webhook address of myapp.com/fax/sent to be notified when an incoming fax is attempting to be sent:
public function sent()
{
$twimlResponse = new SimpleXMLElement("<Response></Response>");
$recieveEl = $twimlResponse->addChild('Receive');
$receiveEl->addAttribute('action', '/fax/received');
return response($twimlResponse->asXML())
->header('Content-Type', 'text/xml');
}
The error that I get from Twilio is essentially empty:
Error 12100 Document parse failure
The Twilio error request inspector shows no head or body.
I have also tried to return a hard-coded view file in place of building the xml:
view fax.sent:
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Receive action="/fax/received" />
</Response>
and then changed the sent function to:
public function sent()
{
return View::make('fax.sent')->header('Content-Type', 'text/xml');
}
This returns the same error message.

Answer 1

Make sure your twiML URL is externally accessible to Twilio (no firewall/IP restrictions, etc) and that it is valid XML with the correct Content-Type.