Is the only way to link PO lines to Vendor Bills through scripting? Having issues trying to upload a CSV for a vendor bill of a PO. We only want to bill half the PO and trying to do a multiple file csv upload I get "Please specify either purchase order list or item/expense list in the request but not both". Googling it makes it seem like it might not be possible as a CSV upload.

you can do it via CSV using the Purchase Order field, but I'm pretty sure you can't partially bill the PO that way. If you reference the PO, it bills the whole thing

Yeah, I can get it to fully bill with the CSV, just not partially.