Programmatically update WordPress post https://smartwp.com/wordpress-insert-post-programmatically/

wordpress-update-post.php

<?php
// Update a post programmatically
$my_post_id = 15
$update_post = array(
  'ID' => $my_post_id,
  'post_title' => 'My new post title',
  'post_content' => 'Overwrite post content',
  'post_status' => 'public'
);

wp_insert_post( $update_post );