Куда вставить json запрос на отправку смс при добавлении новости?

$message = array(
 "username" => "123456789",
 "password" => md5("password"),
 "phone" => "375296890043",
 "text" => "Hello, World!"
);
$messageQuery = http_build_query($message); // returns username=123456789&password=1fa...
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, 'http://api.rocketsms.by/simple/send');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, $messageQuery;
$result = @json_decode(curl_exec($curl), true);
if ($result && isset($result['id'])) {
 echo "Message has been sent. MessageID=" . $result['id'];
} elseif ($result && isset($result['error'])) {
 echo "Error occurred while sending message. ErrorID=" . $result['error'];
} else {
 echo "Service error";
}