How to read feature entity loaded from geoserver

CesiumJS
1

i have created a simple feature data with polygons and inserted the information into the PostGIS db

table as follow:
CREATE TABLE polys (
id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
name VARCHAR(64),
poly GEOMETRY(POLYGON, 4326)
);

inserted all polygons features as follows:

INSERT INTO
polys (name, poly)
VALUES
( ‘name’, ST_MakeEnvelope(, , , , 4326) );

I created a workspace, store then loaded a layer in the GeoServer.

Then I was able to access the polygon vector layer created as follows from cesiumjs

const parameters = {
version: ‘1.1.0’,
format: ‘image/png’,
srs: ‘EPSG:4326’,
transparent: true,
};

const webMapServiceImageryProviderOptions = {
    url: geoServerUrl + "/workspace/wms",
    layers: layer name,
    parameters: parameters,
};

const imageryLayer = new Cesium.ImageryLayer(new Cesium.WebMapServiceImageryProvider(webMapServiceImageryProviderOptions));

viewer.imageryLayers.add(imageryLayer);

//================
However, once I try to read the selected polygon feature with the following:
var pickedObject = pickEntity(click. position);

The result is always [object Object]

even accessing object id, type,data …etc
the result “cannot read properties of undefined (reading ‘id’)”

how can I read all of the property values of the selected feature?