There isn't much information provided to work with, however, a eLearning Quiz does not allow file uploads by default. Neither does the Surveys App, which could have been considered a workaround.

But, what you can do (if you don't want to get into customizing your Odoo) is to utilize the Documents App. You can for example define a folder and set its sharing options to Anyone with the link: Editor - Must have the link to access:

You may as well just create a (sub-)folder per Student and share a personal link with everyone to (try to) prevent frauds. If your Students have portal access, you can also get a step further and set them as owners to their dedicated folders so they can access their own workspace from the portal only.

The features of the Documents App, unfortunately, aren't documented and described in one place. To get more information, you can check for example these slides:

• https://www.odoo.com/slides/22
• https://www.odoo.com/slides/slide/10394 (related to invoices, but concepts explained here and in the subsequent videos are applicable to other areas as well, for example the chapter about requesting missing files: https://www.odoo.com/slides/slide/10399)