function __construct($clientid, $secret)
 {
     //Get oauth token to access Itero API
     $verbose = fopen('php://stderr', 'w');
     $curl = curl_init();
     $data = http_build_query(array('grant_type' => 'client_credentials'));
     curl_setopt_array($curl, array(CURLOPT_URL => self::$oAuth, CURLOPT_POST => 1, CURLOPT_POSTFIELDS => $data, CURLOPT_HTTPAUTH => CURLAUTH_BASIC, CURLOPT_USERPWD => "{$clientid}:{$secret}", CURLOPT_RETURNTRANSFER => true, CURLOPT_VERBOSE => true, CURLOPT_STDERR => $verbose));
     $response = curl_exec($curl);
     $this->exit_on_error($curl);
     $token = json_decode($response);
     self::$auth = "Authorization: Bearer " . $token->access_token;
 }
<?php

include 'config.php';
include 'iteroapi.php';
//Get event data
$json = json_decode(file_get_contents('php://input'));
$event = $json->Event;
$contractid = $json->ContractId;
//Exit if received event is not an "account created" event
if ($event != 'AccountCreated') {
    handle_error(422, "Not an 'account created' event");
}
//Fetch contract and customer data from Itero
$itero = new IteroAPI($clientid, $clientsecret);
if (!$itero) {
    handle_error(500, "Could not initialise itero");
}
$contract = $itero->get_contract($contractid);
if (!$contract) {
    handle_error(500, "Could not fetch contract");
}
$customer = $itero->get_customer($contract->CustomerId);
if (!$customer) {
    handle_error(500, "Could not fetch customer");
}
//Get mongodb instance
$m = new MongoClient($GLOBALS['mongodb'], array("connect" => TRUE));
//$m = new MongoClient();
if (!$m) {
    handle_error(500, "Could not open mongodb");
}
<?php

include 'config.php';
include 'iteroapi.php';
$contractid = $_GET['contractid'];
// Get a default self service portal URL
// from Itero for a sepcific contract
$itero = new IteroAPI($clientid, $clientsecret);
$token = $itero->get_selfservice_token($contractid);
if (!$token) {
    handle_error(500, "Could not fetch token");
}
$portalurl = $token->Url;
?>

<!doctype html>
<html>
	<head>
	    <title>Customer Portal</title>
	</head>
	<body>
		<a href="/customers.php">Back to customer list</a>
		<iframe width="100%" height="2000px" src="<?php 
echo $portalurl;
?>
"></iframe>
	</body>
</html>