当GET路径不存在时，我如何自动返回404？

const express = require('express');
const app = express();

// 其他路由处理...

// 通配符路由，处理所有未匹配的路径
app.get('*', (req, res) => {
  res.status(404).send('404 Not Found');
});

// 启动服务器
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

server {
  listen 80;
  server_name example.com;

  root /path/to/website;

  location / {
    # 其他配置...
    try_files $uri $uri/ /404.html;
  }

  error_page 404 /404.html;
}

import React from 'react';
import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';

// 其他路由配置...

// 404页面组件
const NotFound = () => {
  return <h1>404 Not Found</h1>;
};

// 路由配置
const App = () => {
  return (
    <Router>
      <Switch>
        {/* 其他路由配置... */}
        <Route component={NotFound} />
      </Switch>
    </Router>
  );
};

export default App;