I have tried printing a FedEx shipping label and am seeing an error returned:

PRO_FORMA_INVOICE is required to process your electronic trade document request. (SHIPPING_DOCUMENT=PRO_FORMA_INVOICE).


Pro Forma Invoice needs to be enabled for some shipping destinations to process the Electronic Trade Document (
ETD) request. This can be enabled in > Shipping > Integrations > FedEx Config > Export Documents section. If ETD is enabled in Fedex Config > Export Documents section, then Pro Forma Invoice will get sent electronically.