Creates a post on a remote WordPress site, using the REST API and an application password

remote_create_post.js

const remote_domain = 'https://example.org', // without trailing slash
      application_password = 'Application password',
      username = 'remote_user_name';

const body = JSON.stringify({
      title: 'Post using REST API',
      content: 'Post content using REST API',
      status: 'publish'
});

const options = {
      cache: 'no-cache',
      mode: 'cors',
      credentials: 'include',
      method: 'POST',
      headers: new Headers({
      	'Content-Type': 'application/json',
      	'Authorization': 'Basic ' + btoa(username + ':' + application_password)
      }),
      body: body
};

fetch(`${remote_domain}/wp-json/wp/v2/posts`, options)
      .then(data => console.log(data));