TestForm.php

<?php

namespace Drupal\dialog_renderer_test\Form;

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

/**
 * Provides a form for testing the drupalAutoButtons dialog option.
 */
class TestForm extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return "dialog_renderer_test_form";
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        return [
            'actions' => [
                '#type' => 'actions',
                'submit_1' => [
                    '#type' => 'submit',
                    '#value' => 'Submit button 1',
                ],
                'submit_2' => [
                    '#type' => 'submit',
                    '#value' => 'Submit button 2',
                ],
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
    }

}