/* Disable Automatic Plugin Updates */
add_filter( 'auto_update_plugin', '__return_false' );
/* Disable Automatic Theme Updates */
add_filter( 'auto_update_theme', '__return_false' );If you want to enable WordPress core updates only and want to disable all plugin and theme auto updates, add this code to your child theme’s functions.php.
Note: If you use any other filters, or codes in wp-config.php, remove them to avoid conflict. If you want to control what kind of core updates you want to receive, visit this article.