ng-package.json Data path ".lib" should NOT have additional properties (externals)

I am updated my npm package from angular 7.2 to angular 8.2, the problem I have now in my ng-package.json is that Property externals is not allowed.?

Here is my ng-package.json

  "$schema": "../../node_modules/ng-packagr/ng-package.schema.json",
  "dest": "../../dist/my-shared-lib",
  "whitelistedNonPeerDependencies": [
    "ngx-toastr",
    "@auth0/angular-jwt",
    "bootstrap",
    "font-awesome"
  ],
  "lib": {
    "entryFile": "src/public_api.ts",
    "externals": {
      "ngx-toastr": "ngx-toastr",
      "@auth0/angular-jwt": "@auth0/angular-jwt",
      "bootstrap": "bootstrap",
      "font-awesome": "font-awesome"
    }
  }
}

I dont know what to do with externals? Thanks in advance