code: public function apply(array $options = [], $return_url = '')
      {
          $data = $this->preOrder($options);
          $data['mweb_url'] = isset($data['mweb_url']) ? $data['mweb_url'] : '';
          if (empty($return_url)) {
              $return_url = $this->userConfig->get('return_url');
          }
          return $data['mweb_url'] . "&redirect_url=" . urlencode($return_url);
      }
docs: 应用并生成参数
  @param array $options
  @param string $return_url
  @return string
  @throws \Pay\Exceptions\GatewayException