Yes, all visitors in spite of age are required to have a ticket. Visitors with Exclusive exhibition tickets need to enter the exhibition within the 30-moment window on the ticket. As amongst Germany's major museums, Pergamon has quite a bit to supply — even if you can't bodily be there. https://www.bastognewarmuseum.be/en/museum-second-world-visits-exhibitions-historic-center-bastogne-belgium/