This example widget moved to the official samples: https://developers.arcgis.com/experience-builder/sample-code/widgets/add-layers/

"Add Layers" - Experience Builder

Example Experience Builder widget showing how to add a Feature Layer to a map.

Demo

Quick Start - Download

1. Download and unzip Experience Builder Developer Edition.
2. Download the latest release from this repository.
3. Unzip the downloaded files, and copy the addLayers folder into the client\your-extensions\widgets\addLayers folder of the extracted Experience Builder files.

Quick Start - Git

1. Download and unzip Experience Builder Developer Edition.
2. Open a new terminal window and browse to the client folder.
3. git clone https://github.com/gavinr/add-layers-experience-builder
4. npm ci
5. npm start
6. Start Experience Builder server per the instructions (in a separate terminal, cd server, npm ci, npm start)

Development

1. Open the client folder as a project in VS Code (or similar code editor).
2. Make sure both scripts are running (in the server folder and client) folder).
3. Every time you make a change to your widget, it will be re-built with webpack automatically.

More

View my other Experience Builder projects here.