Unity .net / nodejs problem

Hello! I would like to ask for help. What could be the problem?

Unity Client

using UnityEngine;
using SocketIOClient;

public class NetworkClient : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        var client = new SocketIO("http://localhost:3000/");
        client.On("connection", socket => {
            Debug.Log("test");
        });
    }
    // Update is called once per frame
    void Update()
    {


    }
}

NodeJS server

const io = new Server();

io.on("connection", (socket) => {
  console.log("test 2")
});

io.listen(3000);

I start both and for some reason there is no communication. What am I wrong about? Thank you in advance for your answer. Have a nice day!

[doghappy]

Is there a line of code missing?

    void Start()
    {
        var client = new SocketIO("http://localhost:3000/");
        client.On("connection", socket => {
            Debug.Log("test");
        });
        await client.ConnectAsync();
        // ^^^^^^^^^^^^^^^
    }

[jurniores]

I created Unity Sample https://github.com/devprog-dev/UnitySocketIOPlugins

don’t click link, just copy and paste on web browser

check it. referenced it here.

Your plugins folder is all in Meta