In order to use uglify-js and uglifycss is quite simple. This will minify your files for slightly quicker load speeds:

doas npm install -g uglify-s uglifycss

To utilize for now (make a script later), simply output the minified file using bash redirection operator:

uglifyjs somefile.js > somefile.min.js
uglifycss somefile.css > somefile.min.css