'url', '#title' => 'Optional URL', '#description' => 'An optional URL field.', ]; $form['url_required'] = [ '#type' => 'url', '#title' => 'Required URL', '#description' => 'A required URL field.', '#required' => TRUE, ]; $form['submit'] = [ '#type' => 'submit', '#value' => 'Submit', ]; return $form; } /** * {@inheritdoc} */ public function submitForm(array &$form, FormStateInterface $form_state) { $form_state->setResponse(new JsonResponse($form_state->getValues())); } }