Order by sku

Hi There,

I tried the code to order on sku

add_filter( 'aws_search_results_products', 'aws_search_results_products' );
function aws_search_results_products( $products ) {
    usort($products, function ($item1, $item2) {
        $a = $item1['sku'];
        $b = $item2['sku'];
        if ($a == $b) {
            return 0;
        }
        return ($a < $b) ? 1 : -1;
    });
    return $products;
}

It is not working. Please check how to fix.

Thankyou!

Adrider