Use MicroKernelTrait to bootstrap application. Rewrote routes, controllers and structure of application a bit. Including use of twig.

src/Controller/PromosController.php

@@ -4,12 +4,15 @@ namespace Krzysiej\RyobiCrawler\Controller;
 
 use Illuminate\Database\Eloquent\Builder;
 use Krzysiej\RyobiCrawler\Models\Product;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
 
 final class PromosController extends BaseController
 {
-    public function __invoke(): void
+    #[Route('/promos', name: 'app_promos')]
+    public function __invoke(): Response
     {
         $products = Product::whereHas('currentPrice', fn(Builder $query) => $query->whereColumn('price', '<', 'productStandardPrice'))->with(['currentPrice'])->get();
-        $this->twig->display('productList.html.twig', ['products' => $products]);
+        return $this->render('productList.html.twig', ['products' => $products]);
     }
 }