- Install this Plugin: https://github.com/Cigaras/IPTV.bundle
- Go to the path in Plex where the plugin is installed on your computer and open the folder with its name "IPTV.bundle". In there go to Contents => Resources and you will find the file "playlist.m3u" that you should open with the notepad and add all the IPTV channels you want and that end in .m3u8.
- Save the file and you're done.
Link: https://forums.plex.tv/t/rel-iptv-bundle-plug-in-that-plays-iptv-streams-from-a-m3u-playlist/44559
Does it work?