Edit file File name : shortcodes.php Content :<?php /** * The 404page Plugin Shortcodes * * @since 11.4.0 * **/ if ( ! defined( 'ABSPATH' ) ) { exit; // Exit if accessed directly } // shortcode to show the url that caused the 404 error add_shortcode( 'pp_404_url', 'pp_404_get_the_url' );Save