Error: TypeError: Cannot read properties of undefined (reading 'createIrisApiEngine')

class VideoCallWidget extends StatefulWidget {
  const VideoCallWidget({
    super.key,
    this.width,
    this.height,
  });

  final double? width;
  final double? height;

  @override
  State<VideoCallWidget> createState() => _VideoCallWidgetState();
}

class _VideoCallWidgetState extends State<VideoCallWidget> {
  late RtcEngine _engine;
  bool _isJoined = false;

  @override
  void initState() {
    super.initState();
    _initializeAgora();
  }

  Future<void> _initializeAgora() async {
    try {
      _engine = createAgoraRtcEngine();
      await _engine.initialize(
        RtcEngineContext(
          appId: appId,
        ),
      );

      _engine.registerEventHandler(
        RtcEngineEventHandler(
          onJoinChannelSuccess: (RtcConnection connection, int elapsed) {
            setState(() {
              _isJoined = true;
            });
          },
          onLeaveChannel: (RtcConnection connection, RtcStats stats) {
            setState(() {
              _isJoined = false;
            });
          },
        ),
      );

      await _engine.joinChannel(
        token: token,
        channelId: channel,
        uid: 0,
        options: ChannelMediaOptions(),
      );
    } catch (e) {
      _printError(e.toString());
    }
  }

  void _printError(String message) {
    print("Error: $message");
  }

  @override
  void dispose() {
    _engine.leaveChannel();
    _engine.release();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return _isJoined
        ? AgoraVideoView(
            controller: VideoViewController(
              rtcEngine: _engine,
              canvas: const VideoCanvas(uid: 0),
            ),
          )
        : Center(child: CircularProgressIndicator());
  }
}