M3U or Xtream Codes: which one should you use?
Most providers send both. Same channels either way. Short answer: use Xtream Codes if you have it.
Xtream Codes
Three fields: server, username, password. The app asks the provider’s server for what it needs, so films and series arrive with posters, years, seasons and episodes, and the guide and catch-up come by themselves.
M3U link
One long link (often with get.php in it) to a single list of everything. Works almost anywhere. The guide is a separate XMLTV link, if your provider has one. Big providers’ M3U files can be hundreds of megabytes.
Worth knowing
Both usually point to the same server, so if one stops working, the other often does too. Your provider’s message may list a second server address: that’s the one to try.
Sofascreen is a player: it comes with no channels or playlists. Use it with content you have the right to watch.