You will write your answers in your notebooks. After you are done, you will click a photo of your page and upload it.
You will be able to upload (max) 5 photos. If your answer pages exceed 5, then you will instead create a PDF and upload it as a single file.
For assignments that require you to submit your work done on a notebook page, you can upload any image file (like a jpg or png) which is clicked from mobile phone camera. There are a lot of tools to create a PDF file - a pdf file can have a lot of pages internally. Use any of pdf creation tools in case you have many pages.