I want to extract the urban area’s.

Like this: https://geodata.nationaalgeoregister.nl/bevolkingskernen2011/ows?SERVICE=WMS&LAYERS=cbsbevolkingskernen2011&TRANSPARENT=true&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A28992&BBOX=124000,443000,156000,464283&WIDTH=778&HEIGHT=499

It seems the urban tag is not sufficient for this.

Is there a way to do this?

It’s rather complicated: OSM doesn’t have a specific tag for this. You can read about some experiments I made years ago. I probably have an old data set including the Netherlands, but it will be out-of-date.