Personal project issue help-why does my scrollbar work on codepen but not on my visual studio code?

Usually when I am about to change something in my code but am unsure I change it on the codepen version of my code then I change it on the real thing.
My code was recently messed up pretty badly and I have had a small setback so I’m re-adding things such as my scrollbar.
When I attempt to integrate it back into my codepen it works
Here is the link to the codepen

and to clarify my visual studio code is EXACTLY copy and paste the same as the code in the codepen yet the scrollbar doesn’t appear.
Would anyone have any insight on what is causing this issue?
My browser is google chrome and anyone who wants any extra info feel free to reply to me.

The codepen link you gave us doesn’t work.

ok here is the link again https://codepen.io/Adama-J/pen/BagNVpy paste that into your browser