问每当我试图发布此错误时，都会显示“加载资源失败:服务器响应状态为500 (内部服务器错误)”

EN

:5000/api/order:1 
 Failed to load resource: the server responded with a status of 500 (Internal Server Error)

 code: "ERR_BAD_RESPONSE"
    config: {transitional: {…}, transformRequest: Array(1), transformResponse: Array(1), timeout: 0, adapter: ƒ, …}
    message: "Request failed with status code 500"
    name: "AxiosError"
    request: XMLHttpRequest {onreadystatechange: null, readyState: 4, timeout: 0, withCredentials: false, upload: XMLHttpRequestUpload, …}
    response:
    config: {transitional: {…}, transformRequest: Array(1), transformResponse: Array(1), timeout: 0, adapter: ƒ, …}
    data: {index: 0, code: 11000, keyPattern: {…}, keyValue: {…}}
    headers: {content-length: '123', content-type: 'application/json; charset=utf-8'}
    request: XMLHttpRequest {onreadystatechange: null, readyState: 4, timeout: 0, withCredentials: false, upload: XMLHttpRequestUpload, …}
    status: 500
    statusText: "Internal Server Error"
    [[Prototype]]: Object
    [[Prototype]]: Error

 useEffect(() => {
        const createOrder = async () => {
            try {
                const res = await userRequest.post('/order', {
                    username: currentUser.username,
                    products: cart?.products.map((item) => ({
                        productId: item._id,
                        quantity: item._quantity,
                    })),
                    amount: cart?.total,
                    address: "India",
                    pincode: "110046",
                    phone: "1234567890",
                    email: "johndoe@xyz.com",
                    shippingPrice: "120",
                    reference: orderNo,
                    paymentMethod: "Cash on delivery",
                    status: "pending"
                })
            } catch (error) {
                console.log(error)
            }
        }
        createOrder()
    }, [cart, currentUser])

const user = JSON.parse(localStorage.getItem("persist:root"))?.user;
const currentUser = user && JSON.parse(user).currentUser;
const TOKEN = currentUser?.accessToken;
const BASE_URL = "http://localhost:5000/api/";

export const userRequest = axios.create({
  baseURL: BASE_URL,
  headers: { token: `Bearer ${TOKEN}` },
});

const router = require("express").Router();   
 router.post("/", verifyToken, async (req, res) => {
      const newOrder = new Order(req.body);
      try {
        const savedOrder = await newOrder.save();
        res.status(200).json(savedOrder);
      } catch (err) {
        res.status(500).json(err);
      }
    });

const mongoose = require("mongoose");

const OrderSchema = new mongoose.Schema(
    {
        username: { type: String, required: true },
        email: { type: String },
        phone: { type: Number, required: true },
        products: [
            {
                productId: {
                    type: String
                },
                quantity: {
                    type: Number,
                    default: 1,
                },
            },
        ],
        amount: { type: Number, required: true },
        shippingPrice: { type: Number, required: true },
        address: { type: String, required: true },
        pincode: { type: Number, required: true },
        status: { type: String, default: "pending" },
        trackingId: { type: String },
        paymentMethod: { type: String, default: "Cash On Delivery" },
        reference: { type: String, unique: true },
    },

    { timestamps: true }

);