I am having an issue sharing OneNote documents to external contacts. We are all using Office 365 Business.
I just found that if I share the document from OneNote to specific people (to my gmail account for example), I am required to enter a login and a password which is not the expected behavior.
But if I navigate the SharePoint Site Assets, find the OneNote document and share it (still to specific people), it correctly shares the file and I am able to click the "send code" button.
So my issue is really why the OneNote does not allow the share to behave correctly?
My users are not tech-savvy so asking them to drill down the site assets to find the file is not an option.