Upload document to shipment via API

Using my Dolibarr
1

I see in the code that this module has not yet been implemented for upload, but it seems like a very useful one and fairly standard…I have included a sample payload of what I think should work…my goal is to use a micro service to pull all draft shipments from the api, validating address, creating shipment in FedEx then uploading the shipping label to dolibarr and setting the tracking number.

payload = {
            "filename": os.path.basename(filepath),
            "modulepart": "shipment",
            "ref": shipment_ref,
            "subdir": "labels",
            "filecontent": encoded_string,
            "fileencoding": "base64",
            "overwriteifexists": "1"
        }