How to add upsell products to Thank You page in WooCommerce

/**
 * @snippet       Adding Upsell Products To WooCommerce Thank You Page 
 * @web           wpcues.com
 * @compatible    WooCommerce 6
 */
 
add_action( 'woocommerce_thankyou', 'wpc_thankyou_upsell', 5 );
 
function wpc_thankyou_upsell() {
   echo '<h2>You may interested...</h2>';
   echo do_shortcode( '[products limit="4" columns="4" orderby="popularity" on_sale="true"]' );
}

Where to add this code?

You can place PHP snippets at the bottom of your theme’s functions.php file. You may need to delete “?>” if you have it there.