Is it possible to generate a blanket return label?

We need to send a return label to a few thousand customers who were inadvertently sent a limited edition item twice (we need some of them back to fulfill other orders….we're going to incentivize recipients with a gift certificate to hopefully get a high return rate).

We use ShipStation and have an account with FedEx. ShipStation doesn't allow batched return labels (only one at a time). Is there such a thing as a blanket return label where we send the same label to all customers? If so, what's that called? I'm trying to find it, and may not be using the right keywords. I have a call into our FedEx rep too, but we're on a time crunch with it, so figured someone here may know.