Sorry to hear that! I have enabled SharedArrayBuffer in the project. Itch says the feature is experimental. That might be the problem. Are you able to try the game on a different device? It's the only solution I can think of.
Hey, me from before. I figured out a potential root cause behind this somewhat common issue.
Apparently attempting to access godot based browser games directly through a game collection somehow fails to detect those features.
Running your game or any other game for that matter outside collections effectively circumvents the issue. Someone at itch.io HQ should have a look at that.