I am using the Microsoft one-note graph API for creating pages according to their demand in HTML. Is there any possibility to create a page with a background image? Because I would like to use it as the background of a fillable form. I should be filled by handwriting with a pen on a tablet in the OneNote app.
Or are there any other, better approaches?
You can definitely create pages - see this link.
The background can be an image or pdf.
I however much prefer to use a template page that you create yourself (directly in one note) and copy using page: copyToSection. This allows you to use the added functionality of onenote such as ruled pages, setting images as backgrounds, etc.