Yii2 Menu widget disable parent item link - yii2-advanced-app

Question

How can I disable only the parent item link and leave its children clickable ? For example - when I click on my parent it should open the submenu and not redirect to somewhere else. And if I click on children it should redirect me.
P.S I red the documentation, searched around google but nothing comes out.
This is my code:
<?php
use backend\models\PageAdmin;
use backend\helpers\BackendPrefix;
use yii\widgets\Menu;
$menu_pages = PageAdmin::find()->where('active=1 AND id_in IS NULL')->all();
$widget_menu_content = [];
foreach ($menu_pages as $key => $page){
$related_pages = PageAdmin::find()->where(['active' => 1, 'id_in' => $page->id])->all();
$widget_menu_content[$key]['label'] = "<i class='{$page->icon}'></i>";
$widget_menu_content[$key]['icon'] = $page->icon;
$widget_menu_content[$key]['url'] = BackendPrefix::PREFIX .'/'. $page->url;
if(!empty($related_pages)){
foreach ($related_pages as $key2 => $rel_page) {
$widget_menu_content[$key]['items'][$key2]['label'] = $rel_page->title;
$widget_menu_content[$key]['items'][$key2]['icon'] = "caret-right";
$widget_menu_content[$key]['items'][$key2]['url'] = BackendPrefix::PREFIX . "/" . $rel_page->url;
}
}
}
?>
<div class="side-mini-panel">
<?=
Menu::widget([
'encodeLabels' => false,
'options' => [
'class' => 'mini-nav',
],
'activeCssClass' => 'selected',
'items' => $widget_menu_content,
'submenuTemplate' => "
\n<div class='sidebarmenu'>
\n<h3 class='menu-title'>{label}</h3>
\n<div class='searchable-menu'>
\n<form role='search' class='menu-search'>
\n<input type='text' placeholder='Search...' class='form-control' />
\n<a href='javascript:void(0)'><i class='fa fa-search'></i></a>
\n</form>
\n<div>
\n<ul class='sidebar-menu'>
\n{items}
\n</ul>
\n</div>",
'linkTemplate' => "<a href='javascript:void(0)'>{label}</a>",
'activateParents' => true,
])
?>
</div
Whit my 'linkTemplate' I am disabling all the links which obviously is not my goal :) ( It should disable the parents only ). Alsom, with what token ( or some other option, because I think items is the only token for the children ) I should append the child item label on this line : \n<h3 class='menu-title'>{label}</h3>. In my case what I get echoed is just {label} like a string.
Many thanks!