Bulk append URL (add word to slug)

Here is your code:

if ( isset($_GET['slug-update']) ) {

    $posts = get_posts();

    foreach($posts as $singlepost) {
        if($singlepost->post_status === 'publish'){
            $post_id = $singlepost->ID;
            $current_slug = $singlepost->post_name;
            $updated_slug = $current_slug . '-word';
        }

        wp_update_post( array(
            'ID' => $post_id,
            'post_name' => $updated_slug ) );
    }

    die('Slug Updated');    
}

Add this to your theme’s function.php. Then run this with www.example.com/?slug-update

P.S. this will only update the default post type ‘post’ (backup the database to be secure)

Let me know if this helped.