How to add files for the Source code (.zip) dowload on GitHub

I wanted to share my program on GitHub. I have a .exe file for the download and the source code for the source code (.zip)

But how can I add something to the Source code thing? I ended up with something like this.

(The source code files are the "Class" ones and the "main" one, and they are not in the Source code) When I dowload the Source Code there is only the redme.md file inside.

You would need to, through GitHub Action:

• create a new artifact, for instance a zip file with your actual sources, using for example montudor/action-zip
• create a release, and upload to said release your artifacts, including the new one created before. You can use softprops/action-gh-release

The idea remains: the "Source code" artifacts automatically created by GitHub are not (from what I can see) modificable.
But you can create your own release and upload/add your own artifacts, including one which would have your source code as you want.