Actions form array overriding to set HTML id attribute

I extend the EntityForm class and I try to override a submission button, to set its HTML ID attribute (try #1). Since it doesn't work, I tried to wrap the button in a wrapper <div>. I tried to wrap with two different ways (try #2 and try #3), but they don't work. The only way I can override the submision button is to set '#attributes' to set the HTML attribute class and to add my own CSS class, but my wish was to set a HTML id attribute. And I wanted to do this overriding in actions() method (not form()).

use Drupal\Core\Entity\ContentEntityForm;

class MyForm extends ContentEntityForm {

  protected function actions(array $form, FormStateInterface $form_state) {
    $actions = parent::actions($form, $form_state);

    $actions['submit'] = [
      '#type' => 'submit',
      '#id' => 'save-button', // <-- try #1
      '#value' => t('Save'),
      '#ajax' => [
        'callback' => '::ajaxCallback',
        'event' => 'mousedown',
        'wrapper' => 'bar-wrapper-1',   // <-- try #2
      ],
      '#prefix' => '<div id="bar-wrapper-2">',  // <-- try #3
      '#suffix' => '</div>',
      '#attributes' => [
        'class' => ['foo'],   // <-- try #4
      ],
    ];

    $actions['submit_wrapper'] = [
      '#type' => 'markup',
      '#markup' => '<div id="bar-wrapper-1"></div>'
    ];

    return $actions;
  }

}

I suppose I can only override the HTML ID within form(), but it looks a little inconsistent because I can override/add a CSS class.

a sample here :

$form['submit'] = [
  '#type' => 'submit',
  '#value' => $this->t('Submit'),
  '#weight' => 99,
  '#attributes' => ['class' => ['ex-black'], 'id' => ['testId']],
  '#prefix' => '<div id="testIdWrapper">',
  '#suffix' => '</div>',
];