Erron when i try to reproduce properties-panel-extension

“TypeError: Cannot add property __, object is not extensible”

When i create a new magic group, like:

i receive an error. Can anyone help me?

I use an angular 13 application, and I don’t have webpack.config.js but tsconfig.json … and i wrote my js file in pure mode (SpellProps.js is in pure javascript and it returns correctly the output) …

in addition to this, i use properties-panel, v. 1.9.0


can anyone help me?