Yes, this is possible. First, search for your desired route and select your connection.
Then tap on “Tickets” and click the person icon in the top right corner. There, you can add a bicycle and/or a pet to your booking.

Please note:
Bicycle tickets are subject to availability. Some trains have a limited number of bicycle spaces. If all spots are already taken, unfortunately, we won’t be able to offer a bicycle ticket for that connection.