Adding sections in World Partition

I’m still new to Unreal Engine and I am trying to figure out how I can import an extremely large real world heightmap. For example if I do it through Houdini I’ve seen someone do the map as a mesh which will not tax memory, then I can add whatever I want to the terrain. But if I use World Partition and do it in sections, but I have not seen how to add to the map. I know getting an entire continent will be a challenge but I can scale it and all my assets and characters as well, then with the limited loading distance hopefully not crashing the system. I have watched about a hundred or more videos trying to find how to do this. Any help is appreciated.