From what I am seeing, ETA Consumer Tutorial 5 does not issue batch request,
it encodes and issues Level 2 requests one by one.
Are you issuing a batch request?
Or running the tutorial 5 as is?
Let's start from what is working for you and build up. Are you able to issue a single request, have you run ETA tutorial 4 and received back data?
There is a simple example of batch request within SDK, both Java and C++, if you are looking to do batch and not level 2, that should help.
If you are looking to do level 2, please make sure level 2 is available from your infra, and your user is permissioned for it, tutorial 5 should run then.