Likely the source website or the group responsible for providing subtitles (indicated by "sub") for the video.
: Since the file is an .m4v , it is highly compatible with most modern players. If you encounter playback issues, use the VLC Media Player , which supports nearly all video codecs and external subtitle files. xxxmmsub.com - t.me xxxmmsub1 - JUFE-562-720-1.m4v