You have one choice at the moment, and another coming up. Currently, the only book that has the artificer class is Eberron: Rising from the Last War . Reportedly, Tasha's Cauldron of Everything will have it, but that will not be out until November. These are, of course, rather pricy solutions, since Roll20 does not offer a "cafeteria style" of content purchase. The only other alternative is to manually input the information.