Launch the function loadJSON() with a html button

Yeah, I know this isn’t your end goal. But when you encounter an error, often you’ll have to troubleshoot and isolate the error. If I was getting a network error, I’d try to visit the URL directly. If I can do that, then I know the URL is okay and the error is elsewhere. If I’m unable to visit the URL directly, then I’d know that maybe the URL was incorrect or the server was down or something.