class StandardHooks

class StandardHooks {
  
  /**
   * Implements hook_form_FORM_ID_alter() for install_configure_form().
   *
   * Allows the profile to alter the site configuration form.
   */
  public function formInstallConfigureFormAlter(&$form, FormStateInterface $form_state) : void {
    $form['#submit'][] = [
      $this,
      'installConfigureSubmit',
    ];
  }
  
  /**
   * Submission handler to sync the contact.form.feedback recipient.
   *
   * @param array $form
   *   Form array.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current form state.
   */
  public function installConfigureSubmit(array $form, FormStateInterface $form_state) : void {
    $site_mail = $form_state->getValue('site_mail');
    ContactForm::load('feedback')->setRecipients([
      $site_mail,
    ])
      ->trustData()
      ->save();
  }

}