2D Map jpg as a guide for 3D Landscape Sculpting

I have an 8192 x 8192 jpg image of a world map

I want to take that and “lay it down” as a single texture spanning the 20mi by 20mi max worldmap in UE4.
So it can be used as a guide to sculpt the landscape

I’ve scanned thoroughly between here, Unity, stackexchange, and a couple other places.
The closest I’ve come across is Parallax Mapping in RPG Maker VX, VX ACE, and MV.
Wherein you can set the x,y canvas to show a background or foreground image, and build “on,” “under,” or “around” that

Either nothing in the past 3-4 months of searching was worded correctly, and I’ve missed this somehow.
Or it’s something that’s possible & hasn’t yet been looked into.
Dead certain there’s a way to do it in a more powerful engine like UE4, if RMMV can do it with just Javascript tho