The method 'create' isn't defined for the type 'RtcEngine' Flutter

Question

I'm integrating Agora video call feature in my flutter app by watching Fluttermap youtube channel. I'm facing following error:Flutter code

_engine = await RtcEngine.create(appId); //.create(appId);
    await _engine.enableVideo();
    await _engine
        .setChannelProfile(ChannelProfileType.channelProfileLiveBroadcasting);
    await _engine.setClientRole(widget.role!); //await _engine.setClientRole(widget.role!);
    //! _addAgoraEventHandlers
    _addAgoraEventHandlers();
    VideoEncoderConfiguration configuration = VideoEncoderConfiguration();
    configuration.dimensions = VideoDimensions(width: 1920, height: 1080);
    await _engine.setVideoEncoderConfiguration(configuration);
    await _engine.joinChannel(token, widget.channelName!, null, 0);

Error List:

1.The method 'create' isn't defined for the type 'RtcEngine'. Try correcting the name to the name of an existing method, or defining a method named 'create'.dartundefined_method

2.The named parameter 'role' is required, but there's no corresponding argument. Try adding the required argument.dartmissing_required_argument Future setClientRole({required ClientRoleType role, ClientRoleOptions? options})

3.'dimensions' can't be used as a setter because it's final. Try finding a different setter, or making 'dimensions' non-final.dartassignment_to_final Please help me.

I'm creating rtcengine for video calls.