How can I display only products in the search results?

add_filter('pre_get_posts','lw_search_filter_pages');
function lw_search_filter_pages($query) {
    // Frontend search only
    if ( ! is_admin() && $query->is_search() ) {
        $query->set('post_type', 'product');
        $query->set( 'wc_query', 'product_query' );
    }
    return $query;
}