If you sell time-sensitive products such as grocery items, Amazon requires you to attach an expiration label on the product.
You need to turn on the Exp. Date (1) in the Add screen, and enter an expiration date before you scan the product.
TurboLister will generate a separate label for the expiration date after the FNSKU label. Based on this video from Amazon, it looks like Amazon uses a separate label for the expiration date.