我可以使用优先购买货件
shipment.Buy(shipment.LowestRate(includeCarriers: new List<string> { "USPS" }, includeServices: new List<string>() { "Priority" }));
如何购买 Media Mail 而不是 Priority?
我尝试 了shipping.Create() 并检查了 shipping.rates 但唯一可用的选项是Priority和Express。