Please follow the below steps to print your shipment labels from Amazon Seller Central, after your shipment has been prepared.
Step 1: Login to your Amazon Seller Central account
Step 2: Hover your mouse over the Inventory option and select Mange FBA Shipments
From the Shipping Queue page click on the Continue with shipping plan button.
[NOTE: The reason why we're supposed to choose this option is because the shipping plan has already been prepared (with items within it)]
Scroll to the bottom and click on the Continue button.
You'll now be on the Recommended prep page. Click Continue.
Scroll to the bottom of the page and click the Print labels for this page button.
NOTE: verify your sheet size and print.