WooCommerce - Change product order of displayed upsells on product pages

funcstion.php

add_filter( 'woocommerce_upsell_display_args', 'change_upsell_order', 20 );
function change_upsell_order( $args ) {
  $args['orderby'] = 'date';
  $args['order'] = 'DESC'; // set ASC for oldest to newest
  return $args;
}