How to extract 7zip archives within flatpak? [closed]

I am currently developing a linux mod manager, and I am having major issues trying to extract 7z archives from within the flatpak.

There is a library called "py7zr" available but I simply can't seem to make the dependencies work.

I would really appreciate it if someone had an idea on how to do this cleanly, I'm sure it's been done hundreds if not thousands of times before... I can't be the only one trying to extract 7z archives in a flatpak.

Here is the issue I opened https://github.com/Allexio/nomm/issues/11 on my project where I explain how I'm generating my python3-modules.json and just my process for the build in general and where the dependencies are going wrong.