The testing center
must provide you with some scratch paper or some alternative (a whiteboard with an erasable pen). So don't be afraid to ask for it if you don't receive any (or ask for some extra paper if you write a lot
). Nowadays most testing centers provide you with a (few) tablet-sized whiteboard(s) and an erasable pen. On the last certification exam I took, I got 3 A4-sized pieces of paper which where erasable as well. So I had plenty to write on
Hope it helps!
Kind regards,
Roel