A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Dear Miles_860
Thank you for reaching out to Microsoft support.
It seems that you are having trouble accessing a shared OneNote Class notebook with your school account due to different domains for login credentials and email addresses.
Given this situation, in order to help you better, we suggest that you contact the support team to provide further help with your concern. The support engineer there has the highest permission and sufficient resources, can help you better from the backend.
If you don't have admin permission in your organization, contact your Office 365 admin to go to **** Microsoft 365 >> Support-> New Service > New Service Request If you have admin permission, you can directly follow the article Get support - Microsoft 365 admin | Microsoft Learn to raise a ticket.
Really appreciate their patience and understanding.
Relation
Stacey