Using https://github.com/okeuday/reltool_util

ct_test_example_SUITE.erl

  ...
    Path = [_ | _] = os:getenv("TEST_DIR"),
    ReleaseConfig = filename:join([Path, "..", "rel", "files", "app.config"]),
    {ok, _} = reltool_util:config_load(ReleaseConfig),
  ...
      ok = reltool_util:application_start(?APPLICATION,
                                        [{listen_ip, {127,0,0,1}},
                                         {listen_port, ?PORT}], infinity),
  ...