https:// is implied if you don't include a protocol. http:// URLs generally will generally not work for security reasons. Note that the URL needs to be a direct download and must support CORS (Access-Control-Allow-Origin: *). GitHub Pages will do this automatically and is known to work well.
I noticed it says "generally" twice. Was this for a reason? Idk
Scroll down to the bottom and you'll see
I noticed it says "generally" twice. Was this for a reason? Idk