Our Warehouse Team could not process your return with just a barcode for printing as it's not the actual prepaid shipping label. This means that we have to wait for UPS to bring the prepaid return label when they drop by the warehouse before we can endorse this.
We suggest that you contact Amazon's Customer Support via chat so they can change this to include the prepaid shipping label.
At first you'll be speaking to a bot but after selecting the concern and providing more details, it will give you the option to speak to a live representative (click the person icon at the bottom, boxed in red).
We can't do this on your behalf as the Amazon agent will be asking for your actual order details.
Here's a sample Return label for reference (initially this only has a barcode but Amazon converted it). Please don't forget that the return method should also be for Pick-up only.