It’s not really meant for real-time usage, but that doesn’t mean it can’t be used. But this issue really puzzled me and I downloaded the model myself to inspect it in Blender. I saw that the UV map (or the texture) was indeed mirrored vertically, but somehow, it still worked correctly, even though it looked like it should not, because the UVs were all wrong in the editor. And it took quite a while to figure out how this was possible. In the Blender shader editor, there is a tab called “Node” in the right sidebar that is opened with the “n” key. This has a section called “Texture Mapping”, and there, the Y-Scale is set to -1, which would explain the mirrored UVs. However, this is internal to Blender and doesn’t carry over to Unity when the model is used there.
The good news is that you can mirror the textures vertically to make them work with the UV map. For the normal map, if you then flip the green channel, the normals should be correct again. However, from looking at the material in Blender, you probably won’t be able to recreate the effect in Unity with standard shaders. The Blender material only renders the bumps from the normal and height maps, but with no base color and transparently over the rest of the model as a decal.
Maybe you can make a material in Shader graph that only displays the bump. This seems to indicate that it is possible: Any recipe for a URP "Normals-Only" Decal SG? No Base Color. Is it bugged?