Would you help to give an advice why ion-toggle cannot show on ion-nav-bar? Many Thanks

Would you help to give an advice why ion-toggle cannot show on ion-nav-bar? Many Thanks.

User
<!-- TABS -->
<ion-tabs class="tabs-icon-top tabs-color-active-positive">
  <ion-tab title="Search" icon-off="ion-ios-pulse" icon-on="ion-ios-pulse-strong" href="#/app/search">
    <ion-nav-view name="tab-search"></ion-nav-view>
  </ion-tab>

  <ion-tab title="Browse" icon-off="ion-ios-chatboxes-outline" icon-on="ion-ios-chatboxes" href="#/app/browse">
    <ion-nav-view name="tab-browse"></ion-nav-view>
  </ion-tab>

  <ion-tab title="Playlist" icon-off="ion-ios-gear-outline" icon-on="ion-ios-gear" href="#/app/playlists">
    <ion-nav-view name="tab-playlists"></ion-nav-view>
  </ion-tab>
</ion-tabs>

<!-- Footer -->
<ion-footer-bar class="bar bar-stable">
    <div class="bar bar-footer bar-stable">
        <button class="button icon ion-email button-calm">我的通知</button>
        <button class="button icon ion-gear-a pull-right"></button>
    </div>        
</ion-footer-bar>        

Menu

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