Travelling abroad

Hi, just looking for some help as I can't seem to find answers on the app. I was wondering how my SIM would work when I am travelling in Norway for at least two months, as I would have to keep topping up my SIM with add-ons, so I wondered if there's an easy switch on smarty so I can just make my whole plan work in Norway instead of keep on topping up my SIM. Thanks :)