@baris I see. Thank you once again.

    socket.on('connect', () => {
        console.log('Connected to the socket server');
        socket.emit('modules.chats.enter',1);
        socket.emit('modules.chats.enter',2);
    });

I have made the above modifications and they have been effective! Thank you very much for your response! I just have a small question. If I, as a user, join many chat rooms, do I also need to iterate and join them all in the socket.connect method?

In a separate JavaScript file, I can monitor the newtopic and newpost events by configuring the code below, but chats.receive is not working. I am a beginner in JavaScript. Can someone tell me how to make it work?

'use strict';

const axios = require('axios');
const FormData = require('form-data');
const io = require('socket.io-client');
const forum = 'https://mynodebb.com/';
const socketUrl = 'wss://mynodebb.com';

async function loginAndGetCookie(url, username, password) {
    try {
        let data = new FormData();
        data.append('username', username);
        data.append('password', password);

        let config = {
            method: 'post',
            maxBodyLength: Infinity,
            url: `${url}api/v3/utilities/login`,
            headers: { 
                ...data.getHeaders()
            },
            data: data
        };

        const response = await axios.request(config);
        const cookies = response.headers['set-cookie'];
        if (!cookies) {
            throw new Error('No cookies found in the response');
        }
        console.log('Cookies retrieved:', cookies);
        return cookies.map(cookie => cookie.split(';')[0]).join('; ');
    } catch (error) {
        console.error('Error during login:', error);
        throw error;
    }
}

async function getCSRFToken(url, cookies) {
    try {
        const response = await axios.get(`${url}api/config`, {
            headers: {
                'Cookie': cookies
            }
        });
        const csrfToken = response.data.csrf_token;
        if (!csrfToken) {
            throw new Error('No CSRF token found in the response');
        }
        console.log('CSRF Token retrieved:', csrfToken);
        return csrfToken;
    } catch (error) {
        console.error('Error getting CSRF token:', error);
        throw error;
    }
}

function connectSocket(url, cookies, csrfToken, roomId, userId) {
    const socket = io(url, {
        reconnectionAttempts: 5,
        reconnectionDelay: 200,
        path: '/socket.io',
        transports: [ "polling", "websocket" ],
        query: {
            _csrf: csrfToken,
            //EIO: 4,
            //transport: 'websocket'
        },
        extraHeaders: {
            'Cookie': cookies
        }
    });

    socket.on('connect', () => {
        console.log('Connected to the socket server');
    });

    socket.on('event:new_topic', function (data) {
        console.log('a new topic was posted', data);
     });
    socket.on('event:chats.receive',function(data){
        console.log("a new chats message：",data)
    })

    socket.on('event:new_post', function(data){
        console.log('a new post',data)
    });

    socket.on('connect_error', (error) => {
        console.error('Connection error:', error);
    });

    socket.on('connect_timeout', () => {
        console.error('Connection timeout');
    });

    socket.on('error', (error) => {
        console.error('Socket error:', error);
    });
}

async function main() {
    const url = forum;
    const username = 'username';
    const password = 'password';
    const roomId = '1'; 

    try {
        const cookies = await loginAndGetCookie(url, username, password);
        const csrfToken = await getCSRFToken(url, cookies);
        
        // Get user ID from login response
        const response = await axios.get(`${url}api/user/${username}`, {
            headers: {
                'Cookie': cookies
            }
        });
        const userId = response.data.uid;

        connectSocket(socketUrl, cookies, csrfToken, roomId, userId);
    } catch (error) {
        console.error('Error:', error);
    }
}

main();