Website/app/backend/TestController.php

<?php

declare(strict_types=1);

namespace App;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Attribute\AsController;
use Symfony\Component\Routing\Annotation\Route;
use Twig\Environment;

#[AsController]
#[Route(
    path: '/',
    name: 'test',
    methods: [Request::METHOD_GET]
)]
final readonly class TestController
{
    public function __construct(
        private Environment $twig,
    ) {
    }

    public function __invoke(Request $request): Response
    {
        return new Response(
            $this->twig->render(
                'sites/index.html.twig'
            )
        );
    }
}