How to run frontend (angular2) and backend (silex)?

Question

Angular

A project is being developed in which the frontend is planned for angular2, the backend for silex.
The question is, which layer should run first and run second? In other words, there is index.php where silex bootstraps and there is index.html where angular bootstraps. Accordingly, the angular components pull the silex routes. Or do they need to be separated into separate hosts / ports?
I hope I wrote clearly)

Answer 1

The problem turned out to be illusory. Solved in an elementary way. At the root of the web server, I created a folder, for example, api. I put index.php with silex bootstrap in it. And I started all the routes with angular through / api /.