How to extrude polygons uploaded in geojson format


I’m just starting to master caesium and immediately ran into a problem: I can’t extrude buildings. I did it using the example from the sandcastle, but I can’t integrate the code
I would be very grateful if you could help with the problem. I am attaching a link to

async function addBuildingGeoJSON() {
  // Load the GeoJSON file from Cesium ion.
  const geoJSONURL = await Cesium.IonResource.fromAssetId(2470752);
  // Create the geometry from the GeoJSON, and clamp it to the ground.
  const geoJSON = await Cesium.GeoJsonDataSource.load(geoJSONURL, { clampToGround: true });
  // Add it to the scene.
  const dataSource = await viewer.dataSources.add(geoJSON);
 const entities = dataSource.entities.values;
  for (let i = 0; i < entities.length; i++) {
      const entity = entities[i];
      const name =;
      entity.polygon.extrudedHeight = 10000; 
  // Move the camera so that the polygon is in view.