The article is in Dutch, somI translated it:
The PostNL crypto stamp, or the NL crypto stamp, is a stamp that is issued in two parts. On the one hand, it is a physical stamp that can also be used ‘normally’ as a stamp. On the other hand, it is a crypto stamp, a digital copy that can be collected, traded and exchanged in the blockchain. Every physical stamp comes with its own QR code. This is required to claim the digital copy. The digital part of the NL crypto stamp is an NFT for the collector.
What makes the NL crypto stamp even more unique is the fact that it emerged from a collaboration with the Austrian Post. The crypto stamp is the first crypto stamp in the world to be issued as a joint issue by two postal companies. When the NL crypto stamp is launched, the Austrian Post will release the Austrian version.
When the NL crypto stamp will be for sale, according to PostNL, is still a surprise. The costs are known. A crypto stamp costs € 9.05, which is the same as a stamp for registered mail.