wp_generate_block_templates_export_file example

/** * Output a ZIP file with an export of the current templates * and template parts from the site editor, and close the connection. * * @since 5.9.0 * * @return WP_Error|void */
    public function export() {
        // Generate the export file.         $filename = wp_generate_block_templates_export_file();

        if ( is_wp_error( $filename ) ) {
            $filename->add_data( array( 'status' => 500 ) );

            return $filename;
        }

        $theme_name = basename( get_stylesheet() );
        header( 'Content-Type: application/zip' );
        header( 'Content-Disposition: attachment; filename=' . $theme_name . '.zip' );
        header( 'Content-Length: ' . filesize( $filename ) );