Drupal 8 Registration form and redirect Home page after show custom message.

Drupal 8 Registration form and redirect Home page after show custom message.

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Drupal\Core\Messenger\MessengerInterface;


/**
 * Implements hook_form_FORM_ID_alter().
 */
function MODULE_NAME_form_alter( array &$form, FormStateInterface $form_state, $form_id ) {
  if ($form_id == 'user_register_form' ) {
    $form['actions']['submit']['#submit'][] = '_redirect_handler';
  }
}

function _redirect_handler($form, FormStateInterface $form_state) {

  // $dest_url = "/";
  // $url = Url::fromUri('internal:' . $dest_url);
  // $form_state->setRedirectUrl( $url );

  $url = Url::fromUri('internal:/'); 
  $response = new RedirectResponse($url->toString()); 
  $response->send();
   
  $message = 'A welcome message with further instructions has been sent to your email address. If you have not seen it check your spam folder.';
  \Drupal::messenger()->addStatus($message);
}