UserLanguageTestForm.php

<?php

declare (strict_types=1);
namespace Drupal\user_language_test\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;

/**
 * Provides a User Language Test form.
 */
class UserLanguageTestForm extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'user_language_test';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['#action'] = Url::fromRoute('user_language_test.post_response')->toString();
        $form['actions'] = [
            '#type' => 'actions',
            'submit' => [
                '#type' => 'submit',
                '#value' => $this->t('Send'),
            ],
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
    }

}