limit search results to only show products

snippet.php

/* Filter search query to only display products */
add_filter('pre_get_posts','lit_search_products_only');
function lit_search_products_only($query) {
 
    if ($query->is_search && !is_admin() ) {
        $query->set('post_type',array('product'));
    }
 
    return $query;

}