So is the rice soaking in water overnight?

If this tool runs in the browser, I bet it’s using the WebUSB API, which Firefox doesn’t appear to support: https://developer.mozilla.org/en-US/docs/Web/API/USB

At least in the US, we usually have flexible tubing that supplies water to the sink. If you’re mildly handy, you should be able to hook it up yourself.

I’ll bite

There’s your problem.