OneNote Class Notebook not show up in App Launcher

Hello,

I'm admin of Office 365 for EDU; The OneNote Class Notebook & OneNote Staff Notebook have been pre-installed and showed in App Launcher. For some reasons they been removed.

Now, we want to turn it back on & show them in App Launcher.

I checked in SharePoint > Settings > Radio buttons Show for those apps; but i don't see them in the App Launcher.

Any way to re-show them in App Launcher?

Thanks.