The sublayers property of a MapImageLayer allows you to dynamically set renderers on the fly for layers in a map service. To do so, you must reference the layer ID of the service layer and assign a renderer to the renderer property of the sublayer.
const layer = new MapImageLayer({ url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer", sublayers: [ { id: 2, renderer: { type: "simple", // autocasts as new SimpleRenderer() symbol: { type: "simple-marker", // autocasts as new SimpleMarkerSymbol() size: 3, color: "white", }, }, }, ], });
To see the default renderers for layers in the map service, either remove the references to the renderers defined in this sample or view the MapImageLayer - Toggle sublayer visibility sample.