get out and chat with the attendant usually, at least that's what I used to do when I was living in Europe in a country where self-service was available only after hours.
It's not very common to do long trips requiring refueling at the end, so most of the time you go to the same gas station for years and as time goes on you end up making friends with the people there, also considering often gas stations are a lot smaller than here and either just have the owner pumping or max 1-2 rotating additional people.
If it's an unfamiliar gas station it really depends, in some cases the attendant will just put the pump in your car and click it so it keeps pumping and go to a different car to get paid in which case you stay inside, but if it's a slow time pre-cellphone days you just got out and chatted for the few minutes it took to refuel
It's not very common to do long trips requiring refueling at the end, so most of the time you go to the same gas station for years and as time goes on you end up making friends with the people there, also considering often gas stations are a lot smaller than here and either just have the owner pumping or max 1-2 rotating additional people.
If it's an unfamiliar gas station it really depends, in some cases the attendant will just put the pump in your car and click it so it keeps pumping and go to a different car to get paid in which case you stay inside, but if it's a slow time pre-cellphone days you just got out and chatted for the few minutes it took to refuel