Add shortcode for search form in Genesis Framework

functions.php

<?php
 
/**
* Search Shortcode Excerpt
* @since 1.1 Genesis 404 Page plugin
* @author Bill Erickson
*/
function search_shortcode() {
  return '<div class="genesis-404-search">' . get_search_form( false ) . '</div>';
}

// Add shortcode for search form in Genesis Framework
add_shortcode( 'genesis-404-search', array( $this, 'search_shortcode' ) );