<nav class="navbar-default navbar-static-side" role="navigation">
    <div class="sidebar-collapse">

        <?php
        $menu = Yii::$app->params['menu'];
        ?>
        <?= wdigital\cms\inspinia\widgets\Menu::widget(
            [
                'options' => ['class' => 'nav metismenu', 'id'=>'side-menu'],
                'submenuTemplate' => "\n<ul class='nav nav-second-level collapse' {show}>\n{items}\n</ul>\n",
                'items' => $menu,
            ]
        ) ?>
    </div>
</nav>
