请问去第三国面签的有遇到需要准备信封和Pre-Paid airway bill的吗？

大家好，
我在这周一预约了3月9号在巴巴多斯的美国大使馆面签，付费确认好时间之后在确认页一开始有这么一段话：

“Standard return service of your visa application documents is included at no extra charge. We offer premium delivery service for an extra fee. Would you like to learn more about optional premium delivery service?

If you choose not to purchase the 'Delivery upgrade' a pre-paid airway bill and envelope must be presented with your application documents at the time of the interview for the return of your documents.”

我选择的的return方式就是默认的去巴巴多斯当地的DHL去取，但是这段话有点把我看糊涂了，直接翻译的意思是如果你要是不选择买这个“Delivery Upgrade"的服务，你需要面试的时候带好一个信封和pre-paid airway bill。

请问大家选择在使领馆所在城市DHL自己去取护照，也需要准备Pre-Paid airway bill和信封的吗？谢谢！

刚刚打电话问了巴巴多斯的美国大使馆，给的回答很模糊。。。