sp-dev-fx-webparts/samples/js-extend-webpack/config/package-solution.json

{
  "solution": {
    "name": "js-extend-webpack-client-side-solution",
    "id": "c7111d96-6665-4d90-8b74-30a533b8c7b4",
    "version": "1.0.0.0"
  },
  "paths": {
    "zippedPackage": "solution/js-extend-webpack.sppkg"
  }
}