you can check my flutter client side code here in github:-GitHub - Sam15b/MediaStream.
But i Suggest you to better way implement this Natively Because when mediasoup_client_flutter support version ^ 0.4.6 is compatible with flutter_webrtc ^0.6.10 if you increase the version of any it throw you error of incompatiable with flutter_webrtc or mediasoup_client_flutter . So i implement this project in Flutter 3.16.9 and Dart 3.2.6 . Because of Incompatibility Issue of flutter packages . And Also in Production Google need Compile and Target Sdk 34 . If new Android Version 16 comes then New Policy of Google will Also be comes with Compile and Target Sdk to 35 Which Also Incompatible with both this flutter packages. I raised this issue to Mediasoup but i see no response from them Mediasoup Client Flutter Compatibility Issue with Flutter WebRTC