CallPage.dart

@override
  void initState() {
    super.initState();
    // initialize agora sdk
    initialize();
  }
  Future<void> initialize() async {
    if (appID.isEmpty) {
      setState(() {
        _infoStrings.add(
          'APP_ID missing, please provide your APP_ID in settings.dart',
        );
        _infoStrings.add('Agora Engine is not starting');
      });
      return;
    }
  await _initAgoraRtcEngine();
    _addAgoraEventHandlers();
    await AgoraRtcEngine.enableWebSdkInteroperability(true);
    VideoEncoderConfiguration configuration = VideoEncoderConfiguration();
    configuration.dimensions = Size(1920, 1080);
    await AgoraRtcEngine.joinChannel(null, widget.channelName, null, 0);
  }