Php AWS获取ASIN的库存量

我正在尝试使用ASIN获取每个亚马逊卖家的商品库存量，

但在我的回复中，我得到了空的库存供应清单，如下所示

<ListInventorySupplyResponse xmlns="http://mws.amazonaws.com/FulfillmentInventory/2010-10-01/">
    <ListInventorySupplyResult>
       <MarketplaceId>ATVPDKIKX0DER</MarketplaceId>
       <InventorySupplyList/>
   </ListInventorySupplyResult>
   <ResponseMetadata>
       <RequestId>582d8e1f-2094-4c04-bad8-98e003f59b8d</RequestId>
   </ResponseMetadata>
</ListInventorySupplyResponse>

ATVPDKIKX0DER
582d8e1f-2094-4c04-bad8-98e003f59b8d

所以，我想知道是否有可能得到所有卖家的库存量？为什么我会得到一个空的结果？提前谢谢

<ListInventorySupplyResponse xmlns="http://mws.amazonaws.com/FulfillmentInventory/2010-10-01/">
    <ListInventorySupplyResult>
       <MarketplaceId>ATVPDKIKX0DER</MarketplaceId>
       <InventorySupplyList/>
   </ListInventorySupplyResult>
   <ResponseMetadata>
       <RequestId>582d8e1f-2094-4c04-bad8-98e003f59b8d</RequestId>
   </ResponseMetadata>
</ListInventorySupplyResponse>