* Merchant Code - Your PayU Merchant Code
 * Secret Key - Your PayU Secret Key
 * Platform - RO | RU | UA | TR | HU
 */
$cfg = new MerchantConfig('MERCHANT_CODE', 'SECRET_KEY', 'RO');
/**
 * Create new API Client, passing the Config object as parameter
 */
$client = new Client($cfg);
/**
 * Will throw different Exceptions on errors
 */
try {
    /**
     * Gets the Three DS return response and interprets its
     *
     * See documentation for Response params
     */
    $threeDSResponse = $client->handleThreeDSReturnResponse($_POST);
    if ($threeDSResponse->getStatus() == 'SUCCESS') {
        echo $threeDSResponse->getReturnMessage();
        die('Success. PAYU RefNo =' . $threeDSResponse->getRefno());
    } else {
        echo $threeDSResponse->getReturnMessage();
        die('FAIL. PAYU RefNo =' . $threeDSResponse->getRefno());
    }
} catch (ConnectionException $exception) {
    echo $exception->getMessage();
} catch (ClientException $exception) {
    echo $exception->getErrorMessage();
}