This sample demonstrates how to add a Legend widget instance to a LayerList widget. This is done by adding the legend string to the panel of the appropriate ListItem in the LayerList widget.
// Add a legend instance to the panel of a// ListItem in a LayerList instanceconst layerList = new LayerList({ view: view, listItemCreatedFunction: (event) => { const item = event.item; if (item.layer.type != "group") { // don't show legend twice item.panel = { content: "legend", open: true, }; } },});view.ui.add(layerList, "top-right");