No tickets are required for New Zutphen Square as it is a public space. There is no admission fee.
As New Zutphen Square is a public urban space, there are no tickets to purchase for entry. It is freely accessible to anyone and functions as part of the city's infrastructure, connecting the train station with the surrounding urban area and the historic center. Therefore, you do not need to look for a ticket office or entrance gate.
Any 'tickets' you might purchase in the vicinity would be for public transportation (trains, buses) at the station or for specific events if they happen to be hosted in the square, which would be separate from access to the square itself. For the square itself, access is unrestricted and free of charge at all times.