Hi Lukas,
I’ve downloaded faker .jar file directly from here and import it into Katalon Studio project, used its sample code and it works properly. Here is the link to it
(v0.14): http://central.maven.org/maven2/com/github/javafaker/javafaker/0.14/javafaker-0.14.jar
import com.github.javafaker.Faker
Faker faker = new Faker();
String name = faker.name().fullName(); // Miss Samanta Schmidt
String firstName = faker.name().firstName(); // Emory
String lastName = faker.name().lastName(); // Barton
String streetAddress = faker.address().streetAddress(); // 60018 Sawayn Brooks Suite 449
println name
You should double check and try again. If possible please provide me the error message in case it still does not work for you.