How to set before handle in ng serve Angular 7?

Question

Angular

Good afternoon! Tell me how to expand or customize the ng serve server? I found the package https://github.com/manfredsteyer/ngx-build-plus Angular itself recommends it, they say you can change the parameters through it.
Added custom file:

"serve": {
          "builder": "ngx-build-plus:dev-server",
          "options": {
            "browserTarget": "frontend:build",
            "extraWebpackConfig": "./webpack.serve.extra.ts"
          },
          "configurations": {

          }
        },

in webpack.serve.extra.ts

console.log("webpack.serve.extra.js");

module.exports = {
  devServer: {
    before: function () {
      console.log(123123);
    },
    port: 9000
  }
};

everything starts in the console, the log is displayed, there are no errors, but the default port 4200 does not change to 9000, not to mention before.
Who did something like that?