Camunda operate - Elasticsearch 'Connection refused'. Why?

Hi, thanks for reply.
My test environment is Windows 11 OS.
Journey with Camunda starts at the first level; download software. No clear at all where is the official repository. Camunda Download Hub | Camunda provides link to Camunda… 7. Not even single word about version 8.
So browsing official Camunda site I have no idea where to find some link to download software. No chance. So normally this is the point where most of people would finish Camunda journey; Camunda 8 is only delivered as SaS (no single word that in can be installed in datacenter)
I spent some time with google and found that Camunda offers ‘self-managed’ edition.
But where’s the repository? Google points me to Camunda 8 Self-Managed | Camunda 8 Docs page. But even there no info if I can istall it as docker image or better as standalone software (only Kubernetes). So, maybe camunda publish something on Github? Google says yes:
GitHub - camunda/camunda-platform: Links to Camunda Platform 8 resources, releases, and local development config
So it should be easy, just use docker-compose-core.yaml, right? No way, docker says this file has errors.
OK, let’s search for docker images on docker site. Bingo; there’s something https://hub.docker.com/search?q=camunda
Should be easy. So I download components, start containers but… there’s no communication between them. Looks like Zeebe is OK but Operate cannot communicate with Elasticsearch.

Anyway, what is the correct way to make this software is installed and working?
Regards