Tips - are additional tips on top of prepaid gratuities expected?

Hello! We’re excited to board our first Disney cruise on August 24th. We’re from Europe and we aren’t sure what appropriate and expected, but we’d like to follow the expected norms. Are the included gratuities enough, or is it expected to tip more on top of that? If it’s expected to tip more on top of that, roughly how much? Is it possible to tip with either cash or card? Thank you!