Alter UPS Order XML Export Data with Order/Coupon/Subscription import export plugin

functions.php

function alter_ups_order_xml_export_data( $order_details ) {

    foreach ($order_details as $key => $value) {

            $order_details[$key]['Shipment']['ShipFrom']['UPSAccountNumber'] = 'xxxxxx'; // UPS Account Number
            $order_details[$key]['Shipment']['ShipmentInformation']['ServiceType'] = 'GND'; // UPS ServiceType
            $orderID = $order_details[$key]['Shipment']['ShipmentKey'];
            $order = new WC_Order($orderID);
            $coupons_list = ' CouponCode:';
            foreach( $order->get_used_coupons() as $coupon) {
            $coupons_list .= $coupon.',';
        } 
        $order_details[$key]['Shipment']['Packages']['Package']['ReferenceNumbers']['Reference1'] = 'OrderId:'.$orderID.$coupons_list;
    }
    return $order_details;
}
add_filter( 'hf_ups_order_export', 'alter_ups_order_xml_export_data', 10, 1 );