I need to add an additional fee to the Armed Forces addresses. For some reason my logistic warehouse charges an additional $10 (+/-) for the USPS Priority shipping to these addresses.

I was able to build a zone definition with all the Armed Forces addresses included in it. But I do not know how to proceed from here.

I thought it would be simple and I could just add an extra fee to this zone but I can't find that in any of the settings and I'm thinking it has to be coded.

Can someone help me with this?

Thanks