I adjusted the box so it will scroll past it's max height with a styled scrollbar, you can replace the code that sits between the two top and bottom quotes with this bit of adjusted code: 

https://www.dropbox.com/scl/fi/cezj48o9gy4kf3b51c726/Untitled.gdoc?dl=0&rlkey=5ixrcs89d8uhl1v2f2gjxp2pq

I also added the full scroll version to the original download file -- you may be able to retrieve that through your email.