You'll probably get a better answer from Vodafone New Zealand's community forums than from the United Kingdom ones!
If those settings even exist, you'll need to "sign in" (top right) to the device and then look for them in the settings menu.
I suspect you may not find the settings you are looking for! Here in the UK VF Mobile Broadband uses what is called CGNAT (Carrier Grade Network Address Translation). CGNAT means you share your WAN address with other users, and as a result, port forwarding is next to pointless.
With port forwarding being next to useless on mobile broadband, maybe if you explored what you are trying to achieve, rather than how you are trying to achieve it?
