This article explains how to delete a notebook created on Microsoft OneNote. This feature is useful for deleting unused notebooks and making more space for new ones. To delete notebooks on OneNote, you need to access your files on OneDrive, where documents synchronized between Microsoft applications are saved.
Steps

Step 1. Open your browser of choice and visit the OneDrive notebooks site
This will take you to the website, where the online version of the OneNote application is located.

Step 2. Click Login
You will then be redirected to a page where you will be prompted to enter the email and password associated with your Microsoft account.
If you don't have an account, you'll need to register the email associated with the Microsoft applications you use and create a password. Only in this way will you be able to access features such as deleting notebooks saved on OneDrive,

Step 3. Select Manage and Delete
This option is located on the right side of the gray panel located at the top of the blocks page (in the middle).

Step 4. Click on the Documents folder
Your OneNote notebooks have been saved in this folder.

Step 5. Click the check mark next to the block you want to delete
It is located in the upper right corner of the icon and appears when you hover the mouse cursor over it.

Step 6. Select Delete
This option is located in a panel located above the files and will allow you to remove the block from your OneNote account.