What is Mac Update tab on GTPL website ?

Hi Everyone,
I am new here and its been like 2-3 years since i got Hatway(GTPL) i was wondering what is Mac update on their website is it for static IP ?.
I have a dynamic IP sadly i called them they said they only have for 10mbps and 2mbps connections i have 3mbps connection.Is there a way that i can port forward and make a static ip without buying one from them ?