Omnipay\WechatPay\Message\CreateOrderRequest::sendData PHP Метод

    public function sendData($data)
    {
        $request = $this->httpClient->post($this->endpoint)->setBody(Helper::array2xml($data));
        $response = $request->send()->getBody();
        $responseData = Helper::xml2array($response);
        return $this->response = new CreateOrderResponse($this, $responseData);
    }