When you share notebooks online, OneNote 2016 keeps them automatically synchronized and up-to-date. If you want to sync changes manually—when you’ve made a lot of changes to a shared notebook and you want to make sure they’ve been uploaded to OneDrive or SharePoint before you shut down your computer, for example—here's how:
In any shared notebook, choose File > Info > View Sync Status.
In the Shared Notebook Synchronization dialog box, look at the shared notebooks you’re connected to.
If a notebook appears out of sync, choose Sync Now or Sync All.
Note: Syncing also downloads any changes that other, authorized users may have made to the shared notebook since your last update.
If you’re having issues getting your notebooks to sync, you can troubleshoot sync errors.