There was a new major release of PyScript late in 2023. It is faster, now has a choice of Python interpreters but is not compatible with previous versions. This makes previous tutorials out of date and previous apps probably won’t work with the new version.
I’ve written a new tutorial that implements a simple data visualisation app, which will bring you up to speed with the new version
PyScript Grows Up
( No paywall but you can also find the article on Medium)