DB Schenker - Ombud Retur

functions.php

<?
/**
 * @snippet       WooCommerce - Adds ADDON to Shipment
 * @author        Redlight Media AB / Christopher Hedqvist
 * @compatible    WooCommerce 3.9.0
 */
function redlight_unifaun_bhp_return( $shipment, $order ) {
    // Only Schenker Ombud
  if( 'BHP' === $shipment['service']['id'] ){
    $shipment['service']['addons'][] = array(
      'id' => 'RETPP',
      'misc' => 'STORE'
    );
  }
  return $shipment;
}
add_filter('ac_wc_unifaun_shipment_data', 'redlight_unifaun_bhp_return', 10, 2 );