Setup IPTV for raspberry pi 4

hi there. I have a raspberry pi 4 running librelec kodi, and for using iptv there is an add on called “pvr iptv simple client”.
The thing is that in this case, my ISP has a type of modem that outputs a single LAN port just for IPTV, which means only one decoder can be connected there. My question is how can I make the raspberry pi to connect to that port and just recieve the channels? there are some configurations on the add on that apparently needs to fed the channels and guides, but I dont know where to get them. Any idea is welcome, thanks