'email', '#title' => 'Email address', '#description' => 'An email address.', ]; $form['email_required'] = [ '#type' => 'email', '#title' => 'Address', '#required' => TRUE, '#description' => 'A required email address field.', ]; $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())); } }