Add some functional to UI

I’d like modify UI to add some functional.

I changed on my site app/frappe/public/js/frappe/ui/listing.js and after execute bench start all changes are in sites/assets/js/list.min.js

But in repo GitHub - frappe/bench: CLI to manage Multi-tenant deployments for Frappe apps I can’t find any .js files.

How can I change some .js or .css file and push them?

The frappe repo is GitHub - frappe/frappe: Low code web framework for real world applications, in Python and Javascript