AMAZON RETURN POSTAGE LABELS CREDIT

After initiating a Seller Fulfilled return, if the buyer doesn’t send the item back, I understand that I am not charged for issuing a refund. However, what happens to the return label? Is the cost automatically refunded if it remains unused, or do I need to request a refund for it? I have assumed that I am not charged for the generated return label when the buyer does not ship the item back—can you confirm if that is correct? The Amazon return process, from a sellers perspective, is incredibly frustrating and difficult to navigate.