Yes, Firefox will work as well (I just tested it to be sure). This app just copies the code to the clipboard, then you can press cmd+v to paste it into the fiel

Yes, Firefox will work as well (I just tested it to be sure). This app just copies the code to the clipboard, then you can press cmd+v to paste it into the field. Once it's copied to your clipboard, you can paste it into any app the needs it, including Firefox.