Just near the start of the lesson you talk about adding a particle effect to use and there would be a sprite image to download, but there isn’t.
Also, the gitlab link for the lesson points to a commit that only contains what appears to be a little cleanup within the scene, but nothing else.
The commit you might have pointed to would probably be the one before, but then that last addendum would be missing?
I would recommend adding a branch for every lesson and then doing a merge at the end, so the merge commit would be the one to point to…