$ streamlink 'https://twitcasting.tv/deoxymole' best -l debug
[cli][debug] OS:         Linux-5.15.0-1-git-x86_64-with-glibc2.33
[cli][debug] Python:     3.9.7
[cli][debug] Streamlink: 2.4.0+76.g73417ce.dirty
[cli][debug] Requests(2.26.0), Socks(1.7.1), Websocket(1.2.1)
[cli][debug] Arguments:
[cli][debug]  url=https://twitcasting.tv/deoxymole
[cli][debug]  stream=['best']
[cli][debug]  --loglevel=debug
[cli][debug]  --player=mpv
[cli][info] Found matching plugin twitcasting for URL https://twitcasting.tv/deoxymole
[plugins.twitcasting][debug] Live stream info: {'movie': {'id': 708601320, 'live': True}, 'fmp4': {'host': '211-133-247-132.twitcasting.tv', 'proto': 'wss', 'source': True, 'mobilesource': True}}
[plugins.twitcasting][debug] Real stream url: wss://211-133-247-132.twitcasting.tv/ws.app/stream/708601320/fmp4/bd/1/1500?mode=main
[cli][info] Available streams: main (worst, best)
[cli][info] Opening stream: main (stream)
[cli][debug] Pre-buffering 8192 bytes
[plugin.api.websocket][debug] Connected: wss://211-133-247-132.twitcasting.tv/ws.app/stream/708601320/fmp4/bd/1/1500?mode=main
[cli][info] Starting player: mpv
[cli.output][debug] Opening subprocess: mpv --force-media-title=https://twitcasting.tv/deoxymole -
[cli][debug] Writing stream to output
[cli][info] Player closed
[plugin.api.websocket][debug] Closed: wss://211-133-247-132.twitcasting.tv/ws.app/stream/708601320/fmp4/bd/1/1500?mode=main
[cli][info] Stream ended
[cli][info] Closing currently open stream...