Add new comment | Drupal 8

Add new comment

 public function buildForm(array $form, FormStateInterface $form_state) {

 $form['set_start_date'] = [
      '#title' => $this->t('START DATE '),
      '#type' => 'date',
      '#attributes' => array('type'=> 'date', 'min'=> '-12 months', 'max' => 'now' ),
      '#date_date_format' => 'd/m/Y',
      '#required' => TRUE,
    ];

 $form['set_end_date'] = [
      '#title' => $this->t('END DATE'),
      '#type' => 'date',
      '#attributes' => array('type'=> 'date', 'min'=> '-12 months', 'max' => 'now' ),
      '#date_date_format' => 'd/m/Y',
      '#required' => TRUE,
    ];
    
 
  $form['actions']['#type'] = 'actions';
  $form['actions']['submit'] = array(
      '#type' => 'submit',
      '#value' => $this->t('Fetch'),
      '#button_type' => 'primary',
    );
    return $form;

}

how can i fetch table from start date to end date on button click