Axios Network Error depending on CORS policy in Node JS

While trying to carry out put axios request the following error occurs:

The CORS module was installed and switched in server.js file, but seems that doesn’t work.
By the way there are no any CORS headers in the request:

So in server.js file the CORS module is implemented. I tried to add {origin: “http://localhost:3000”} in brackets but that didn’t work. The brackets are empty.

server.js:

const express = require("express");
const mongoose = require("mongoose");
const apiRoutes = require('./routes/apiRoutes');
const path = require('path');
const cors = require("cors")
require("dotenv").config();

const app = express();
const PORT = 3001;
app.use(cors());
app.use(express.static(path.join(__dirname, 'images')));
app.use(express.urlencoded({ extended: false }));
app.use(express.json());
app.use(apiRoutes);

mongoose
    .connect(process.env.MONGO_URL)
    .then(res => console.log("The connection to the Database was carried out successfully."))
    .catch(error => console.log(`The Error while connecting to the Database occured: ${error.message}`))
    
app.listen(PORT, 'localhost', error =>
    console.log(error ? `The Error occured: ${error.message}.` : `The Listening Port is ${PORT}`)
);

the route:

router.put("/api/newAd/:creationDate", (req, res) => {
  console.log(req.body);
  // Ad.updateOne({ creationDate: req.body.creationDate }, {
  //   textInfo: req.body
  // })
})

the client side:

    const saveAndPlace = () => {
        axios.put(`/api/newAd/${creationDate}`)
        .catch(err => console.log("error", err))
    };

So why these errors occur? And why the headers are not shown in the network panel?