req.body пуст, когда отправляю запрос через fetch. Почему? Как исправить?

//Front:
fetch("http://127.0.0.1:3000/test", {
    method: "post",
    headers: {
        "Content-type": "application/json; charset=UTF-8",
    },
    body: JSON.stringify("heeey")
})
.then((data)=>{
    return data.json();
})
.then((res)=>{
        console.log(res);
})
.catch((err)=>{
    console.log('Request failed ', err );
});
//Back:
const express = require('express')
const bodyParser = require("body-parser");
const app = express();
const urlencodedParser = bodyParser.urlencoded({extended: false});

const port = 3000
app.use((req, res, next)=>{
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Content-Type");
    if(req.method == "OPTIONS"){
        return res.status(200).send('ok');
    }
    next();
})
app.post('/test', urlencodedParser, (req, res) => {
    console.log(req.body)
    res.status(200).send({
        t: 1,
        d: 2,
        test: req.body
    })
});
app.listen(port, () => console.log(`Example app listening on port ${port}!`));```