public function getData()
    {
        $this->validate('currency', 'description', 'encryptionKey', 'returnUrl');

        // The test mode is included to determine the redirect URL.

        return [
            'VPSProtocol' => $this->VPSProtocol,
            'TxType' => $this->getTxType(),
            'Vendor' => $this->getVendor(),
            'Crypt' => $this->generateCrypt($this->getCryptData()),
            'TestMode' => $this->getTestMode(),
        ];
    }