const dropdowns = $('#your_menu_id_here').children('.menu-item-has-children')

if (dropdowns.length > 0) {
  dropdowns.each((i, el) => {
    const toggle = $('> a:first-child', el)

    toggle
      .addClass('dropdown-toggle')
      .attr('data-toggle', 'dropdown')
      .attr('role', 'button')
      .attr('aria-haspopup', 'true')
      .append(' <span class="caret"></span>')

    $('ul.sub-menu', el).addClass('dropdown-menu')

    toggle.dropdown()
  })
}