Leaving the Netherlands
If you leave the Netherlands you need to de-register within five (5) days prior to leave and you can request a proof of de-registration. You do need to make an appointment with your municipality. If your partner or child(ren) leave the Netherlands, they must also deregister.
You can find here information for departure of the Netherlands. It is helpful to read this first.
Deregister from the Netherlands
More information: deregister for non-EU international: https://ind.nl/en/emigrating-leaving-the-netherlands