code: public function kernelView(GetResponseForControllerResultEvent $event)
      {
          $request = $event->getRequest();
  
          if (!$request->query->has('locale')) {
              return;
          }
  
          $controllerResult = $event->getControllerResult();
          $locale = $request->query->get('locale');
  
          if ($controllerResult instanceof Paginator || is_array($controllerResult)) {
              foreach ($controllerResult as $model) {
                  if ($model instanceof Localizable) {
                      $this->localeService->localize($model, $locale);
                  }
              }
          } elseif ($controllerResult instanceof Localizable) {
              $this->localeService->localize($controllerResult, $locale);
          }
  
          $event->setControllerResult($controllerResult);
      }
docs: Filter the returned data for a given locale
  
  @param \Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent $event