ECK with elastic helm-charts

How to deploy ELK using helm charts, but set ECK as cluster manager?

From what I understand, ECK requires to set "Kind" in yaml manifest to "Elasticsearch" (specific custom resource) instead of "StatefulSet".

Hey there. So these are two different things:

There are the GitHub - elastic/helm-charts: You know, for Kubernetes

and there is the ECK operator (which has its own Helm chart to deploy itself) The latter is the recommended way to deploy Elasticsearch, Kibana, etc. on Kubernetes.

You cannot migrate an Elasticsearch cluster deployed via the Helm chart into an operator managed cluster just by changing the kind in the resource.