Shopify has two order statuses to note whether an order has shipped yet:
Pirate Ship will only import Unfulfilled orders. If you want to import an order that is currently marked as Fulfilled in Shopify, you'll need to manually change the order back to Unfulfilled in Shopify's dashboard and then refresh Pirate Ship's import page:
Note: When you buy a label for a Shopify order with Pirate Ship, the order is automatically marked as Fulfilled in Shopify. To avoid accidental duplicate shipping, you will need to request a refund for the label in Pirate Ship before Pirate Ship will display it again, even if you manually mark the order as Unfulfilled in Shopify.