问在这里，成功存储消息的数据显示。但是数据没有显示在mongo数据库中。有什么问题吗？

EN

e.prventDefault();

const onSubmit = (e) => {
    
e.prventDefault();

    const data = {
      name: name,
      age: age,
      city: cityArray,
    };

import React from 'react';
    import {
      BrowserRouter,
      Routes,
      Route,
    } from "react-router-dom";
    import AddPosts from './components/AddPosts.jsx';
    import Posts from './components/Posts.jsx';
    import UpdatePosts from './components/UpdatePosts.jsx';
    import UserRegister from './components/UserRegister';
    import UserLogin from './components/UserLogin';
    
    
    export function App() {
      return(
       <div>
        <BrowserRouter>
        <Routes>
        <Route path="/" element={ <UserLogin/>}/>
        <Route path="/user/register" element={ <UserRegister/>}/>
          <Route path="/add" element={<AddPosts/>}></Route>    
          <Route path="/view" element={<Posts/>}></Route>  
          <Route path="/update/:id" element={<UpdatePosts/>}></Route>
          
          </Routes>
          </BrowserRouter>
      </div>
      );
    }