Powerpoint storage

I was working on powerpoint and I took notes for school on ppt. But when I was ready, it didn't save my notes which made me watch the whole lecture again. After this time, my ppt saving was not working how it should be working.

It was slow and did not react when I wanted to save.

Then I went looking to my storage of my iPad Pro 2020 and I noticed that the powerpoint app has 9 GB of storage? But all my ppt are saved on my iCloud account in files documents. But when I delete a presentation in the powerpoint app, it disappears from bij document files as well.

How can I save my ppts to my documents in iCloud, without storing it on the powerpoint app.

Because I use this for school, the amount of ppt will increase a lot so it is not a good idea to storage it on the app? Please help me. thanks in advance