AndySu90210
It seems impossible.
What we can see in the browser are the html document rendered from the server, and the javascript files, css files and images linked to the html page and cookies. So perhaps you could transform your javascript code to be almost unreadable, but all the element the public is seing (html pages, images, css, javascript) are "public", so easy to download.
Only the html code (front end), css, javascript files created with PHP, Node.js, Python, Java, GOlang, Ruby , could be downloaded, and not from those back-end languages.