I would send data (POST method) and fetch that in fetch. Problem is that I send data via axios or jQuery, I can see this var like $_POST. In fetch not. Look at this example script.js

const update = {
    title: 'A blog post by Kingsley',
    body: 'Brilliant post on fetch API',
    userId: 1,
};
const options = {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
    },
    body: JSON.stringify(update),
};

fetch('test.php', options)
    .then(data => {
        return data.json();
    })
    .then(post => {
        console.log(post);
    });

test.php

<?php
    print_r(json_encode($_REQUEST));

In console.log, it displays an empty array. How can I send and fetch post data via fetch?