Error
Your browser does not allow to read local files.
Might wanna fix that so people can actually try this out :P
Changing the Firefox setting did NOT work.
Only thing I can find online about it in regards to RPG Maker is this thread: https://forums.rpgmakerweb.com/index.php?threads/error-your-browser-does-not-all...
I've been playing RPG Maker games on browsers for a while now and I've NEVER seen this issue in my life. It looks like it might be an issue when you deploy the game on your side.
Also: Tried this on Chrome, and got:
Error
Failed to initialize graphics.
It might be a permission issue. It looks like the same error I get with RPGM MV games running in HTML in a freshly installed Firefox.
If you're in Firefox, changing a browser configuration might help. To do this, type about:config in the address bar and press enter. In the new page, search for "privacy.file_unique_origin" (without quotation marks) and set it to false.
If you're in Chrome, sorry, but I don't know if there's a similar config