code: public function validateOptIn()
      {
          $optInValue = \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter('rvw_oegdproptin');
          if ($this->isReviewOptInValidationRequired() && !$optInValue) {
              return false;
          }
  
          return true;
      }
docs: Validate current request data, regardless if form was submitted or not
  
  @return bool