get https://marketplace.walmartapis.com/v4/fulfillment/download-label///
The primary goal of this service is to download the labels of booked shipments.
Currently, download label API enables the download of carrier labels for small parcel
shipments. After submitting a label generation request, you can call the Download Label
API. If the label request is still being processed, the response will return a status of 202
(Accepted). Once the labels are ready, the API response will include a PDF file containing
the labels.