Search Form Drupal

 Add placeholder, icon

 function register_form_search_block_form_alter(&$form, &$form_state, $form_id) {
     
  if ($form['#id'] == 'search-block-form--2') {
        $form['keys']['#prefix']= '<div class="icon"><i class="fa fa-search" aria-hidden="true"></i>';
        $form['keys']['#attributes']['placeholder'] = t('Search for Topics');
        unset($form['actions']['submit']);
         $form['keys']['#sufix']= '</div>';
  }
}