OneNote for Windows 10 automatically syncs all of your notes for you. If you prefer, you can choose to sync notebooks manually whenever you want.
On any page, click the Show Notebooks button .
In the pane that appears, right-click the name of the notebook you want to sync. (On a touch device, press and hold the notebook name.)
Select Sync, and then choose to Sync This Notebook, or Sync All Notebooks.