You need install iPlayTV from Apple TV app store . it Cost 6.99 USD 

App in app store : https://apps.apple.com/app/iplaytv/id1072226801

Then follow  this steps :

Install IPTV on iPlayTV

1. Select ADD Playlist

   open iPlayTV and select Add Playlist

2. Choose Xtream Server

   There are 3 ways to add IPTV list: M3U link (Remote playlist file) , Downloaded m3u list (Local file) and Xtream Server . We recommend to use Xtream server method which provide you more feature like EPG and play list auto update .

3. Enter Xtream server details

   You need enter the Xtream server details : Server URL ,Username and password which provided by your IPTV provider .
   You can Extract Xtream server details form M3u link too.

4. Note : you need enter a name for playlist , It can be any name ( install-iptv in this case)
   Select Save
   

5. Channels and VOD loading

   In last the playlist load channels, VOD and EPG informations.
   Done

FAQs

How to find Xtream Codes details ?

You can extract Xtream Codes information from M3u link . look at this example:

How to zapping channel list when a channels play ?

You can slide finger from left to right over remote control to slide zapping channel list .

How to show current channel EPG?

Slide your finger from right to left over remote control .

Use left/right arrows to navigate the slideshow or swipe left/right if using a mobile device

Source