@leopessanha just to confirm, you uploaded a pre-tiled 3D Tileset to your account, right?
I believe the way Cesium ion’s transform tool works is by editing the transform of the root node in the tileset JSON.
You should be able to do this the same way you access the tiles, using the Cesium ion REST API. If you just need to look at it for debug purposes the easiest way is to look at the network tab while you’re loading your asset. Alternatively, most properties in the JSON are parsed and accessible on the loaded 3d tileset instance in CesiumJS, so the root transform for example would be