Create a Post with fetch in Wordpress with REST API and authentication with nonces

shortcode-create-story.js

(function($) {
  const postData = {
    title: 'Lorem ipsum dolor sit amet',
    content: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
    status: 'publish'
  };

  window
    .fetch(`${scriptVars.endpoint}`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'X-WP-Nonce': scriptVars.nonce
      },
      credentials: 'same-origin',
      body: JSON.stringify(postData)
    })
    .then(() => window.alert('success'));
})(jQuery);

shortcode-create-story.php

<?php
/*
Plugin Name: Shortcode Create Story
Description: Inserts Markdown editor and submit button to a post
*/

add_shortcode('figment_create_story', 'figment_create_story_shortcode');

function figment_create_story_shortcode()
{
}

add_action('wp_enqueue_scripts', 'figment_enqueue_create_story_script');
function figment_enqueue_create_story_script()
{
  /*Enqueue the styles and scripts the edit in markdown depends on*/
  wp_register_style('font_awesome', 'https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css');
  wp_register_style('simple_mde_css', 'https://cdn.jsdelivr.net/simplemde/latest/simplemde.min.css');
  wp_enqueue_style('font_awesome');
  wp_enqueue_style('simple_mde_css');

  wp_enqueue_script('simple_mde_js', 'https://cdn.jsdelivr.net/simplemde/latest/simplemde.min.js', []);
  
  /*Enqueue the file with the fetch request*/
  wp_enqueue_script('create-story-script', plugin_dir_url(__FILE__) . '/shortcode-create-story.js', ['jquery', 'simple_mde_js']);

  /*Inject variables into the script, including the authentication nonce*/
  wp_localize_script('create-story-script', 'scriptVars', [
    'endpoint' => esc_url_raw(rest_url('wp/v2/posts/')),
    'nonce' => wp_create_nonce('wp_rest')
  ]);
}