Samsung rolls the update to Android 10 for people with a Galaxy S9 or S9 +. At the moment, the update seems to be initially only available in Germany and the United States. In the coming period it will also be the turn of the Netherlands.
How fast Dutch people can download the update is not yet known. Samsung mentions March as the official release date for Android 10. So it can take a few days, but in the worst case it can also take a few months.
This update is for people who now have Android Pie on their device, not for those who have a beta version installed.