3d tileset coordinates

Hello all,
I have a 3d model( obj file), I convert it to 3dtileset format. I want to know the coordinate.
My obj file’s coordinate base on EPSG:4326, I converted it to 3dtileset, I specified the orignal coordinate( lon,lat, heit). So I want to know, the region’s coordiante( I think the location of the volume) determines the location of the model or the coodinates of vertices in gltf part?

I want to match my model precisely to the earth but confused by the coordinates system. Any idea? I’d appreciate that a lot.