woocommerce search by sku and title ajax

Pls Try this code

if(is_numeric($search_keyword)){
$args = array(
            'posts_per_page'  => 3,
            'post_type'       => 'product',
            'meta_query' => array(
                array(
                    'key' => '_sku',
                    'value' => $search_keyword,
                    'compare' => 'LIKE'
                )
            )
        );
}

else if(is_string($search_keyword)){
  $args = array(
    's'                   => $search_keyword,
    'post_type'           => 'product',
    'post_status'         => 'publish',
    'ignore_sticky_posts' => 1,
    'posts_per_page'      => 3,
    'orderby'             => $ordering_args['orderby'],
    'order'               => $ordering_args['order'],
    'suppress_filters'    => false,
    'tax_query'           => array(
        array(
            'taxonomy' => 'product_visibility',
            'field'    => 'term_taxonomy_id',
            'terms'    => $product_visibility_term_ids['exclude-from-search'],
            'operator' => 'NOT IN',
        ),
    ),
);}