$form['set_end_date'] = array (
  '#type' => 'date',
  '#title' => t('set end date'),
  '#required' => TRUE,
);

$form['actions']['#type'] = 'actions';
$form['actions']['submit'] = array(
  '#type' => 'submit',
  '#value' => $this->t('Fetch'),
  '#button_type' => 'primary',
);
return $form;