Export map ue5 to blender

Hello,
Sorry to bother you with that,
But I would like to know if someone know how to export an entirely map from UE5 to Blender?
I tried to export and import into blender as an fbx file but the result is a black and white map with multiple cubes so I guess that it’s a little bit more complicated.
I tried to do it again with only the castle but the result is the same ( attached picture)

Thanks you very much for your help,