Hi @KLonHJ
I would recommend that you have a look at React developer information:
https://stackoverflow.com/questions/33527653/babel-6-regeneratorruntime-is-not-defined
You should use the versions as defined by Metabase:
https://www.metabase.com/docs/latest/developers-guide.html
Please don't create multiple topics about the same problem.
Just for reference: Can not add a function in app-main.js