themes-wordpress/lineup/patterns/search.php

<?php
/**
 * Title: Search
 * Slug: lineup/search
 * Inserter: no
 */
?>

<!-- wp:search {"label":"","showLabel":false,"placeholder":"<?php echo esc_html_x( 'Search...', 'This is a placeholder text in a search field', 'lineup' ); ?>","buttonText":"<?php echo esc_html_x( 'Search', 'This is what a search button says', 'lineup' ); ?>","buttonUseIcon":true} /-->