Disable reaching a node by its internal path (node id)

use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Drupal\node\NodeInterface;

function MYMODULE_preprocess_page(&$variables) {
  if (isset($variables['node']) && \Drupal::currentUser()->isAnonymous()) {
   $node = $variables['node'];
   if ($node instanceof NodeInterface) {
     if ($node->getType() === 'your_node_type') {
       $path = \Drupal::request()->getPathInfo();
       if (preg_match('#/node/\d+/*$#', $path)) {
         throw new NotFoundHttpException();
       }
     }
   }
 }
}