First make sure your Kodi is updated to latest version so that the guide below doesnt seem misguiding.

The tutorial below is for PVR IPTV Simple client addon on Kodi.

1-Open Kodi client
2-Select System
3-Select TV or if your version is not updated it might appear as Live TV
4-Select General
5-Select Enabled
6-Once a pop-up appears saying you have no PVR client enabled, just select OK
7-Scroll down and choose PVR IPTV Simple Client
8-Select Enable
9-Select Configure
10-In General, select M3U Playlist URL
11-Now add the M3U url you`ve got from your provider into this section
12-Select OK twice
13-Reboot Kodi

Now, once Kodi starts, on your screen you should see TV or Live TV, Click that and choose a channel to play.