Add WooCommerce Orders as a SearchWP Source.

searchwp-customizations.php

<?php

// Add WooCommerce Orders as a SearchWP Source.
// @link https://searchwp.com/documentation/knowledge-base/search-woocommerce-orders/
add_action( 'plugins_loaded', function() {
	if ( class_exists( 'WooCommerce' ) ) {
		add_filter( 'searchwp\sources', function( $sources ) {
			$sources[] = new \SearchWP\Sources\Post( 'shop_order' );

			return $sources;
		} );

		add_filter( 'searchwp\post_stati\shop_order', function( $post_stati ) {
			return array_merge( $post_stati, [
				'wc-pending',
				'wc-processing',
				'wc-on-hold',
				'wc-completed',
				'wc-cancelled',
				'wc-refunded',
				'wc-failed',
			] );
		} );
	}
} );