Hi @marco.rossi,
To the best of my knowledge, the method that I shared returns the elevation of the terrain data at a given latitude and longitude. Are you adding a 3D Tileset on top of the terrain? If so, is it a point cloud dataset?
I know that it is possible to access the height of points in a point cloud:
However, I would have to check in with the rest of the team regarding other types of 3D Tiles.
Best,
Sam