I am working on the new theme using webpack building css and js. There is no problems to work with styling sass/css, but the theme doesn't read js files after builded webpack. Is there way to get this?
I am not sure that I understand the question?
Are you building a new theme for Backdrop?
Can you provide a little more information about the specifics of your problem?
I am trying to use packages and modules from the npm registry to generate the css and js needed for my theme. I use webpack to manage packages and get .css and .js output files. According to the developer documentation https://docs.backdropcms.org/documentation/creating-sub-themes I need to add files
style sheets [all]  = mystyle.css
scripts  = myscript.js
to the .info file. And it works correctly for both of them if I use a standalone js file. But the js file I get as output from webpack is not. This works for Drupal 9, so I thought it might work for Backdrop too. Let me know if I'm wrong.