code: private function getContactFormMethod()
      {
          $method = self::CONTACT_FORM_METHOD_DEFAULT;
  
          if ($configMethod = \OxidEsales\Eshop\Core\Registry::getConfig()->getConfigParam('OeGdprOptinContactFormMethod')) {
              $method = $configMethod;
          }
  
          return $method;
      }
docs: Get currently selected contact form opt in method
  
  @return string