While Shopify's backup option is activated if the app is unavailable, PrettyDamnQuick's fallback option is displayed in case *none* of the delivery methods apply to a specific order.

For example if your delivery methods apply for orders shipped to all states except New Jersey, an order shipping to New Jersey will see a fallback shipping rate called "Shipping" with the fallback rate amount your enter.

To activate it, just switch it on in your Delivery methods, and enter the rate you'd like applied for the fallback option.