The loading indicator takes advantage of Angular interceptor. Hence the progress bar will appear on each single or "banch" of Ajax requests.
The loading indicator uses nprogress
npm install nprogress --save
npm install @types/nprogress --save
You can customize color of a progress bar through nprogress-ovewrite.scss
@import "../node_modules/nprogress/nprogress.css";
@import "<path>/nprogress-ovewrite.css";
Include LoadingIndicatorModule.forRoot() into your app module.