Charging delivery fees by post code

[FoxFizz]

Hi,

I'm on the Basic Shopify Plan, paying monthly. 

I have ShipFee loaded, and all the rural delivery postcodes in New Zealand are loaded. I would like to be able to charge no delivery fee for delivery to non-rural addresses and a delivery fee to addresses with a rural post code.

How do I proceed from here?

I can't see how to link the app and my instance of Shopify any further. It may be possible if I pay annually - I'm not sure. 

Any help would be much appreciated. 

- Matt