The PreOrder Now app does not currently offer a built-in feature to add or remove shipping charges specifically for preorder items.
Instead, your default shipping profile in Shopify will apply to all products in the cart, including both preorder and regular items.
If you need special shipping rules for preorder items:
You may need to adjust your default shipping profile in Shopify to better reflect the shipping cost structure you want.
If you’re unsure how to modify your Shopify shipping settings, we recommend checking out Shopify’s shipping documentation or contacting their support team.