Multicast as LiveTV from Povider for XG Firewall

Hello,

I need an instruction for multicast configuration LiveTV Streaming on Sophos XG Firewall.  I receive live tv from my provider over mutlicast. On XG Firewall I can not configure it. :-( Why is sophos so complex for Multicast? I tried this url https://community.sophos.com/kb/en-us/123135 instruction. That it didnt work :-( and really this instruction is for me not logical (I dont understand wy a  receiver (Client) needs a multicast IP-Adress??) 

Do you have mybe a better or easier instruction? Terrible that sophos is unable for a simple mutlicast streaming. :-(

Thanks for your help

Regards

Ugur