Ошибка запроса к серверу Node.js

import express from 'express'; 
import bodyParser from 'body-parser' 
const app = express(); 
const port = 8080; 
 
 
 
 
const MongoClient = require('mongodb').MongoClient; 
 
const url = 'mongodb://localhost:27017/'; 
 
MongoClient.connect(url, (err, client) => { 
 
	const db = client.db('diplom'); 
	const collection = db.collection('lessons'); 
 
	if (err) throw err; 
	console.log('Connection established'); 
	collection.find().toArray((err, results) => { 
                  
        console.log(results); 
        client.close(); 
    }); 
}); 
app.use((req, res, next) => { 
    // Website you wish to allow to connect 
    res.setHeader('Access-Control-Allow-Origin', '*'); 
 
    // Request methods you wish to allow 
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE'); 
 
    // Request headers you wish to allow 
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type'); 
 
    // Set to true if you need the website to include cookies in the requests sent 
    // to the API (e.g. in case you use sessions) 
    res.setHeader('Access-Control-Allow-Credentials', false); 
 
    // Pass to next layer of middleware 
    next(); 
}); 
app.use(bodyParser.json()) 
 
 
app.get('/admin', (res) => { 
	const datag = { 
		"name": "Вася", 
		"age": 35, 
		"isAdmin": false, 
		"friends": [0, 1, 2, 3] 
	} 
	/* res.writeHead(200, {'ContentType': 'text/html'}); */ 
	res.send(datag); 
	res.write('fuck') 
	res.end(); 
}); 
 
const server = app.listen(port, () => { 
	console.log('Server is up and running on port ' + port) 
});

let header = new Headers({ 
   /*  'Access-Control-Allow-Origin':'*', */ 
    'Content-Type': 'application/json', 
    'Accept': 'application/json' 
}); 
 
let myInit = { method: 'GET', 
               mode: 'cors', 
			   header: header,  
			}; 
 
const endpoint = 'http://localhost:8080/admin'; 
 
function Request () { 
	fetch(endpoint, myInit) 
		.then(res => res.json()) 
		.then((res) => { 
			  console.log(res); 
		}) 
} 
 
 
export default Request;