如何通过FedEx REST API设置DDU（收件人付税）发货？

使用FedEx REST API发货时，DDP（发货人付税）的实现代码如下：

$rate_data ["requestedShipment"]["customsClearanceDetail"] = [ 
    'dutiesPayment' => [
        'paymentType' => 'SENDER',
        'payor' => [
            'responsibleParty' => [
                'accountNumber' => [
                    'value' => ACCOUNT_NUM
                ]
            ]
        ]
    ],
    'commodities' => $commodities,
];

但设置DDU（收件人付税）时遇到问题：原本以为只需将'paymentType'改为'RECEIVER'，但操作后FedEx返回错误：

[errors] => Array
    (
        [0] => Array
            (
                [code] => RATE.PAYMENTTYPE.NOTALLOWED
                [message] => Selected Payment Type is not allowed. Only allowed payment type is SENDER. Please update and try again.
            )

    )

查阅文档发现PaymentType仅支持SENDER作为有效值，请问该如何设置让收件人支付税费？

FedEx REST API中，DDU（收件人付税）是默认模式，不需要配置dutiesPayment节点。当你省略该节点时，系统会自动认定由收件人承担进口税费及清关费用。

修改后的代码如下：

$rate_data ["requestedShipment"]["customsClearanceDetail"] = [ 
    'commodities' => $commodities,
];

API的设计逻辑是：仅当需要发货人承担税费（DDP）时，才需配置dutiesPayment并指定paymentType为SENDER，DDU无需额外设置。

内容的提问来源于stack exchange，提问作者Scott C Wilson