labels-healthy-forest.js

// to get layer id: 
view.map.layers.forEach(l => console.log(l.id, l.title))

// replace the id below with the one you want to modify:
const layer = view.map.findLayerById("189b5aed56b-layer-75");

// clone renderer, modify it and set it back on the layer:
let renderer = layer.renderer.clone();

renderer.uniqueValueInfos.forEach(info=>{
    const symLayer = info.symbol.symbolLayers.getItemAt(0)
    if (symLayer.size > 0) {
        symLayer.anchor = "bottom"
        info.symbol.callout = {
            type: "line",
            size: 3,
            color: "#219E5A",
            border: {
                color: [0, 0, 0, 0]
            }
        };
        info.symbol.verticalOffset = {
            screenLength: 30,
            maxWorldLength: 5000,
            minWorldLength: 0
        }
    }
}
)
layer.renderer = renderer;

// set labeling info and enable labels on the layer:
layer.labelingInfo = [{
  symbol: {
      type: "label-3d",
      symbolLayers: [{
        type: "text",
        material: {
          color: [255, 255, 255]
        },
        background: {
            color: "#219E5A"
        },
        font: {
          size:  10,
        }
      }]
    },
  labelExpressionInfo: {
   expression: "Replace($feature.Name, '*', TextFormatting.NewLine)"
  },
  where: "Category = 'Label'"
}]
layer.labelsVisible = true;