Change of Postcode

Hello. I have just registered my apartment on Booking.com 

It is said that I need to verify my apartment. To do so I have been sent a 6-digit number by a post from Netherlands. The problem is that I wrote down the address of my apartment and the postcode of the main post department in my city. Can I change the postcode? Or where should I wait for the code from Booking - at the address of my apartment or main post department?

I would be happy if you could help me.

Best wishes,

Anna