Well, in general, there is no particular type of coffee bean used to make an espresso. You can use any type of coffee bean. There are some who advise you to use a medium roast or the less oily variant to get the best-tasting espresso. But there is no rule about it. Your personal preference is always the best basis for choosing which coffee bean you will use. Commonly used coffee beans are Robusta and Arabica. You can check these variants out and see which one you prefer.