How do I open .html files and have them work with my external CSS and Javascript files on iPad? (iPad Mini 2, iOS 12.4.3)

I am really frustrated here. I really would like this to work on my iPad, because it's for an important project, but no matter what I do, my html files refuse to connect to my .css files, my .js files, and any multimedia I have. Meanwhile, my site works like a charm on my Kindle Fire and all computers I've tried it on. Furthermore, I can't even open up my html files in a web browser, but when I open them in the default iOS file manager, they show up with no javascript, no css, and no multimedia.