The ATA needs to be sent by the Port Authority. If this is not the case, you can have this specified via the Service Desk. For this, you must send an e-mail with permission from the Port Authority to the e-mail address of the Portbase service desk. We can use this to assist you in still specifying the ATA for the trip.
There is an exception for the port of Vlissingen. No ATA (or ATD) is specified for this port.