Hi, can you please paste the error message you get? This should be using features that are supported widely as of 2022 and I regularly test on Firefox LTS.

I'm just getting "invalid response." in a 500 response from the `anubis/api/pass-challenge` endpoint – weirdly, when I added breakpoints and stepped through the code myself, it worked, but if I load again, I get the error. Maybe there's a timing component? (Firefox stable)