Так вот же, в документации к пакету написано
If you need to separate sections of the menu then just add the header option to item in items
'items' => [
['label' => 'Gii', 'iconType' => 'far' 'icon' => 'file-code', 'url' => ['/gii']],
['label' => 'Debug', 'icon' => 'dashboard-alt', 'url' => ['/debug']],
['label' => 'MAIN NAVIGATION', 'header' => true], // here
// ... a group items
['label' => '', 'header' => true],
// ... a group items
['label' => '', 'header' => true],
// ... a group items
To add a badge for a item:
'items' => [
[
'label' => 'Mailbox',
'iconType' => 'far',
'icon' => 'envelope',
'url' => ['/mailbox'],
'badge' => '123'
],
]
В элемент массива $items добавляете
...
'badge' => '<span class="badge badge-info right">123</span>'
...