I have a plane ticket including a rail@fly ticket for the Deutsche Bahn (DB). I want to use a City Night Line train, which has a compulsory reservation.
But where can I find this reservation option? I’ve read in many places that I have to go to www.bahn.de, but that is not very detailed. I cannot find an option to insert my rail@fly ticket and only pay for the reservation.
How do I have to do this?