Angular config maps in kubernetes
This one from medium should be fine for your purposes: https://medium.com/@ychetankumarsarma/how-to-manage-angular-application-configurations-for-different-environments-with-docker-and-8ff8c55a1c7d.

It is good because:


It shows a test / development scenario.
It notes that it is a good / accepted technique to use environment variables to drive config.
It shows you how to create a config map with a literal value (as an example).
It shows you how to read that environment variable into your app environment properly.


There is also a working sample app noted here -> https://github.com/chetanku/frontend-env which you should be able to "just start up" and work backwards from.