How do I ignore the assets folder when uploading Android project to github?

I'm trying to upload my android project to github, but the assets is too large > 300mb. What is the correct way to place the assets path inside the .gitignore file? Inside the gitignore it currently looks like this, but after trying to upload it to github, it didnt work so I'm assuming it's incorrect:

/build
/.app/src/main/assets

This is the path of the .gitignore

-DesktopFolder
    -app
       -src
          -main
             -assets
             -java
             -res
       .gitignore

Edit:

I have also tried

/app/src/main/assets

and

/src/main/assets

but neither work

Edit 2:

I've also tried creating a .gitignore file inside the assets folder with a asterisk * but that doesn't work either.

from How do I ignore the assets folder when uploading Android project to github?