laipower/wp-content/themes/generatepress/404.php

<?php
/**
 * The template for displaying 404 pages (Not Found).
 *
 * @package GeneratePress
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

get_header(); ?>

	<div id="primary" <?php generate_do_element_classes( 'content' ); ?>>
		<main id="main" <?php generate_do_element_classes( 'main' ); ?>>
			<?php
			/**
			 * generate_before_main_content hook.
			 *
			 * @since 0.1
			 */
			do_action( 'generate_before_main_content' );

			generate_do_template_part( '404' );

			/**
			 * generate_after_main_content hook.
			 *
			 * @since 0.1
			 */
			do_action( 'generate_after_main_content' );
			?>
		</main>
	</div>

	<?php
	/**
	 * generate_after_primary_content_area hook.
	 *
	 * @since 2.0
	 */
	do_action( 'generate_after_primary_content_area' );

	generate_construct_sidebars();

	get_footer();