Summarize this article:

Macchiato is made with espresso, and each standard double shot will require 0.6 to 0.7 ounces (18 to 21 g) of coffee beans, depending on how strong you want the shot. Measure the beans and transfer them to a coffee grinder. Grind the beans until they're finely ground. Finely ground coffee beans are about the size of salt grains. This is the ideal grind for espresso. You can also buy pre-ground espresso beans from grocery stores and coffee shops if you don't have a grinder.

Summary:
Grind the beans.