AM 7.3, Install silently throws a java.net.ConnectException: Connection refused exception

I went through the suggested docs but it is not clear how to install AM that way to use the mentioned File Based Configuration (FBC).

During the AM installation there are only two options for configuration store:

  • embedded - OpenAM embedded OpenDJ server
  • dirServer - ForgeRock OpenDJ or Oracle Directory Server Enterprise Edition

If I am correct all available options uses some kind of DS at the background. I can not see here FBC option to select. I am sure I misunderstood something, but what?