The file …../erp/modules/accounting/assets/js/admin.js/ will be reset and get your customization removed once WPERP gets updated. So, this is not an appropriate way to customize the plugin.
Anyway, compiling process is kinda hard unless you are a Pro developer. You need to have Node installed. Then you’ll need to run ‘npm install’ command, then ‘npm run build’.
Got it! Thanks for the pointer. I think I managed to run it successfully. I will also make sure that the changes won’t get overwritten by a new WP ERP version (will merge my customizations every time).
The exact command I used was npx webconfig --config webpack.config.js