Well, the possibility to convert / activate the voucher into a ticket at the airport Terminal 1 is no longer available because the office is closed. Nevertheless, I was able to use the public bus into the city free of charge upon request from the driver. Activation was possible without any problems at the head office on O'Conell Street. The hop on-hop tour was very good. The first time I rode the entire route without getting off. The next day I used the trip again with boarding and alighting at individual stations. The buses always came on time. - Very good.