Putting IPTV channels into Enigma 2 bouquets can be a challenging task.
There is a possibility of using DreamBoxEdit which supports IPTV channels or streams
but I am a fan of a harder way where you are adding iptv channels directly into enigma 2 channel lists files (*.tv files).
For this you need remote access to your receiver via ssh connection.
I suggest you use WinSCP software.

When you are done with connecting to your receiver,
go to to /etc/enigma2 and open bouquets.tv file.
Add this line into the file (EDIT: this step is actually not needed – restart of E2 is enough
that receiver detects new userbouquet.iptv.tv file):
#SERVICE 1:7:1:0:0:0:0:0:0:0:FROM BOUQUET “userbouquet.iptv.tv” ORDER BY bouquet

“userbouquet.iptv.tv” is the name of the file which contains iptv channels list.
You can rename it to something else,
I just used name iptv. Remember that words “userbouquet” and “tv” cannot be changed.
You can only change word “iptv”.

Then you need to create userbouquet.iptv.tv file using notepad++
and then continue with putting iptv channels into this file.
In my case added channels look like this:

#NAME IPTV Streams
#SERVICE 1:0:0:0:0:0:0:0:0:0:http%3a//
#SERVICE 1:0:0:0:0:0:0:0:0:0:http%3a//
#SERVICE 1:0:0:0:0:0:0:0:0:0:http%3a//