A sequence of custom parameters appended to the URL of all requests related to a layer.
Referenced by: Building Scene Layer (BuildingSceneLayer), Catalog Layer (CatalogLayer), CSV Layer (CSV), Feature Layer (ArcGISFeatureLayer), GeoJSON Layer (GeoJSON), Image Service Layer (ArcGISImageServiceLayer), Integrated Mesh 3D Tiles Layer, Integrated Mesh Layer (IntegratedMeshLayer), Map Service Layer (ArcGISMapServiceLayer), Object 3D Tiles Layer, Oriented Imagery Layer (OrientedImageryLayer), PointCloud Layer, Scene Layer (ArcGISSceneServiceLayer), table, Tiled Image Service Layer (ArcGISTiledImageServiceLayer), Tiled Map Service Layer (ArcGISTiledMapServiceLayer), Vector Tile Layer (VectorTileLayer), Voxel Layer, Web Coverage Service Layer (WCS), Web Map Tile Service Info, WMS Layer (WMS)
Example
{
"key": "7FA3B7BABB7B45749BF3C6358F2B228F"
}