Twig integration in CI4

Thanks for replay
I might not have understand your question
anyway, here is my code
In controller

PHP Code:

use \Kenjis\CI4Twig\Twig;
class Trace extends BaseController
{
    protected $twig;

    public function initController(
        \CodeIgniter\HTTP\RequestInterface $request,
        \CodeIgniter\HTTP\ResponseInterface $response,
        \Psr\Log\LoggerInterface $logger
    ) {
        parent::initController($request, $response, $logger);
        $this->traceModel = new TraceModel();
        $this->twig = new Twig(['functions' => ['dateSlash']]);
    }    
[...]
    public function add()
    {
        $validation =  \Config\Services::validation();
        if ($this->request->getMethod() === 'post') {
            if ($this->validate('traceRules')) {
            [...]
                $this->session->setFlashdata('success', 'trace modifiée');
                return redirect()->to('/trace/index');
            } else {
                return redirect()->back()->withInput();
            }
        } else {
            $trace = new \App\Entities\trace();
        }
        return $this->twig->render('trace/add', [
            'validation' => $validation,
            'trace' => $trace,
            'url' => base_url('/trace/add'),
            'titre' => 'Ajouter',
        ]);
    } 


in view

PHP Code:

{% extends "default.twig" %}

{% block content %}
<form name="trace" method="post" action="{{ url }}">

  <div class="field">
    <label class="label">Nom</label>
    <div class="control">
      <input class="input" type="text" name="lastname" value="{{ trace.lastname }}">
    </div>
    {{ form_error('lastname') }}
  </div>