我正在尝试使用Axios将表单数据发送到后端MongoDB。如果 Postman 发送邮递请求，则API工作正常，但如果请求来自前端，则无法命中API。我已附上错误的屏幕截图：

前端代码：

const res = await axios.post('http://localhost:8000/api/users/adduser', {
      name: name,
      email: email,
      phone: phone,
      message: message
    })
    .then(function (response) {
      console.log(response);
    })
    .catch(function (error) {
      console.log(error);
    });
  }

后端代码：（节点. js）

//ADD USER
router.post("/adduser", async(req, res) => {
    console.log("add-user api");
    try{
        console.log(req.body);
        let newUser = new User({
            id: Date.now().toString(36),
            name: req.body.name,
            email: req.body.email,
            phone: req.body.phone,
            message: req.body.message
        });
        const user = await newUser.save();
        res.status(200).json(user);
    }catch(err){
        res.status(500).json(err);
    }
});

索引.js：

const express = require("express");
const app = express();
const dotenv = require("dotenv")  
const mongoose = require("mongoose")

//Models
require('./models/User')
//Routes
const userRoute = require("./routes/users")

dotenv.config();
//A middleware which will Extract req.body for us
app.use(express.json());

mongoose.set("strictQuery", true);
mongoose.connect(process.env.MONGO_URL, {
    useNewUrlParser:true,
    useUnifiedTopology: true,
})
.then(console.log("Connected to MongoDB"))
.catch(err => console.log(err));

app.use("/api/users", userRoute);

app.listen(8000, () => {
    console.log(`Server is running on port 8000.`);
  });