Gel pens are similar to pens, but have the characteristics of ballpoint pens. Some gel pens don't need much effort. There are many gel pens, you can choose one.
I guess you are preparing for the exam. In fact, what pen you use is not very important, but your psychological effect. You can use any pen according to your usual habits, or simply prepare that the color of the pen and ink should be the same, so that you are prepared. I wish you good results in the exam!