If you require the details of an order for shipping purposes then you can call the following using GET

<apiurl>/api/shipment/details?supplieruid=&retailercode=&customercode=&ordernumber=

Where

SupplierUid is your unique supplier id that can be obtained from our support crew

RetailerCode is the predefined retailer code that can be obtained from our support crew. Note this field is optional
CustomerCode is the customer code from you accounting system that the order was created with. Note this field is optional 

OrderNumber is the order number you want the details about

The call will return the following structure in  json

Any errors will return the following with status = "error"