<script src="<?= $this->asset('js/jquery-ui.min.js', 'contao-components/jquery-ui') ?>"></script>
<script>
  jQuery(function($) {
    $(document).accordion({
      // Put custom options here
      heightStyle: 'content',
      header: '.toggler',
      collapsible: true,
      active: false,
      create: function(event, ui) {
        ui.header.addClass('active');
        $('.toggler').attr('tabindex', 0);
      },
      activate: function(event, ui) {
        ui.newHeader.addClass('active');
        ui.oldHeader.removeClass('active');
        $('.toggler').attr('tabindex', 0);
      }
    });
  });
</script>