为何Socket.io出现‘Not Found’错误？Node+Express项目求助

我正在学习用Socket.io实现项目中的私聊功能，后端基于Node.js+Express框架，预期访问/chat路由时返回聊天页面，但目前访问该路由时触发Not Found错误。

相关代码 #

app.js #

import http from "http";
import express from "express";
import bodyParser from "body-parser";
import cookieParser from "cookie-parser";
import dotenv from "dotenv";
import { router } from "./routes/web.js";
import { connectDb } from "./db/connectDb.js";
// configuring dotenv
dotenv.config();

// initialize app
const app = express();
// server
const node__server = http.createServer(app);

// static files
app.use(express.static('../frontend'));

// middlewares
app.use(bodyParser.urlencoded({ extended: true }));
app.use(cookieParser());

// load routes
app.use("/", router);

// define template engine
app.set("view engine", "ejs");

// connecting database
connectDb(process.env.DATABASE_URL);

// Listening to browser port
node__server.listen(process.env.PORT, () => {
    console.log(`App is listening at http://localhost:${process.env.PORT}`);
});

export { node__server };

chatHandle.js #

import { Server } from "socket.io";
import { node__server } from "./app";
// socket 
const io = new Server(node__server);

io.of("/chat").on("connection", (socket) => {
    console.log(socket.id);
})

client.js（聊天页面脚本） #

const socket = io("/chat");
socket.on("connect",()=>{
    console.log("client connected");
})

错误截图 #

内容的提问来源于stack exchange，提问作者SIDDHARTH SINGH