Everyone can view the current and complete agenda here, but only registered, logged-in users can book. As soon as you are logged in, further tabs will appear with bookable agendas.
Here just to have a look:
Wähle den Event, klicke auf „buchen“. Chose an Event, click on „book“. Choisis ton événement, appuie sur « book »
Here would be the “Book” button. However, you are on the public “Read only” agenda, you cannot book here. Log in and go to the “Buy Ticket” tab to book.