Drupal - Redirect to the front page with a different language

You can try this code

 <?php

 use Drupal\Core\Url;
 use Symfony\Component\HttpFoundation\RedirectResponse;

 $language = Drupal::languageManager()->getLanguage('vi');
 $url = Url::fromRoute('<front>', [], ['language' => $language]);
 $response = new RedirectResponse($url->toString());
 $response->send();