No, it’s a Cesium3DTileset. Usually consisting of a tileset.json and a lot of .pnts files. There are converters out there. Also see this comment.
That asset is stored using Cesium Ion, I also don’t know much about it. But you can also get it using Cesium3DTileset.fromUrl(), and that URL points to your Cesium3DTileset file.
What is your original data format? las? laz?