The frontend is split in two different components: an angular frontend and a Java backend. The Java backend is configured using environment variables. Yet, as angular can not be configured via environment variables, a manual configuration may be necessary. For any user that just wants to use the default configuration no config changes are necessary!
The frontend is configured here. The only important configuration is backendUrl. This options specifies where the Java backend is deployed. If the frontend is bundled with the backend, an empty string has to be provided. Yet, if the backend is deployed somewhere else, specify the according url here, e.g. localhost:8080.