Send an SMS using curl through Plivo.

plivo_curl.php

<?php

# Plivo AUTH ID
$AUTH_ID = '';

# Plivo AUTH TOKEN
$AUTH_TOKEN = '';

# SMS sender ID.
$src = '';

# SMS destination number
$dst = '';

# SMS text
$text = '';

$url = 'https://api.plivo.com/v1/Account/'.$AUTH_ID.'/Message/';
$data = array("src" => "$src", "dst" => "$dst", "text" => "$text");
$data_string = json_encode($data);
$ch=curl_init($url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
curl_setopt($ch, CURLOPT_USERPWD, $AUTH_ID . ":" . $AUTH_TOKEN);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
$response = curl_exec( $ch );
curl_close($ch);

?>

I needed to add this to make it work:
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

not working for me.. No response from the API request.