I explained what “download ESM from skypack” means here:
In the link above I’m using SortableJS so you’d open their cdn URL and grab the other URL inside. For example:
- Open https://cdn.skypack.dev/sortablejs@1.13.0?min
- Then grab the path and open the final URL: https://cdn.skypack.dev/-/sortablejs@v1.13.0-mei9zfSyMp6mF9rZklbl/dist=es2020,mode=imports,min/optimized/sortablejs.js
- Place the file above in the app/assets/javascripts/libraries and the stimulus help from your importmap will pickup the import correctly.
I hope this helps.