Can you give us more details? From what I can tell you work with unity. If the game doesn't load at all you might have this problem: https://itch.io/t/927410/the-webgl-version-of-my-game-is-not-loading
Else you will have to check your code for errors. Try recompiling with developer mode and have a look in your browser console.
First you need to find out weather the problem is on your end or on itch.io. Basically dose it run on your computer at all?
Since you haven't corrected me I will continue asuming that you work with unity. Is your original webgl build file still on your computer? You shouldn't be downloading it from itch.io every time you want to test it. Just open the index.html file in a browser.
Please give me the exact error massage. "Some java script failed" will only get you the answer "then fix it".
