How do I export OneNote data from my account?

Summary

OneNote for Business (which is what we use) doesn’t allow you to export entire notebooks. 

You’ll need a OneNote personal account. If you don't have one, create one at https://account.microsoft.com/

1. Login to the OneNote Desktop App (on windows or MacOS) with both your Business and Personal accounts
2. In your School account, open the Section or Page that you want to export/transfer to your Personal account (the coloured tabs are sections - it doesn't work with section groups, which are the level above)
3. Right click the Section or Page and then choose the “Move/Copy” option.
4. Choose the target Notebook or Section on your Personal OneNote that you want to “move” the Section/ Page to or make a “copy” of the section/page. 
5. If you’re moving or copying large files this make take a few moments. Give OneNote and your internet connection some time to sync up

Details

For more detailed instructions, see this Microsoft article