Looks like they’re using feature detection and Firefox is missing that feature https://github.com/webcompat/web-bugs/issues/76550#issuecomment-858285637 https:

Looks like they’re using feature detection and Firefox is missing that feature https://github.com/webcompat/web-bugs/issues/76550#issuecomment-858285637 https://github.com/webcompat/web-bugs/issues/76550#issuecomm...