Pixel streaming - it will be no local?

I followed this guide and managed to set things up just by opening up a port. But I get a weird assertionError…

The guide: https://www.seagullcompany.com/blog/how-to-stream-with-unreal-pixel-streaming-engine/

The error message:
Assertion failed: PeerConnection
[File:D:/Build/++UE4+Licensee/Sync/Engine/Plugins/Media/PixelStreaming/Source/PixelStreaming/Private/Streamer.cpp] [Line: 226]

Section of source-code on this:

225: rtc::scoped_refptrwebrtc::PeerConnectionInterface PeerConnection = PeerConnectionFactory->CreatePeerConnection(PeerConnectionConfig, webrtc::PeerConnectionDependencies{ Session.Get() });
226: check(PeerConnection);
227: Session->SetPeerConnection(PeerConnection);
228: Players.Add(PlayerId) = MoveTemp(Session);
229: }