Connecting to stand-alone Elasticsearch instance

Can OpenDistro’s Kibana be connected to a standalone Elasticsearch instance? Or is it necessary to use OpenDistro Elasticsearch only?
Pardon me if the question sounds stupid.

I think yes, but you would need to disable some odfe functionalities like the security (kibana) plugin, and config the default host to http://elasticsearch from https one. I never try but it should be working fine. You can check out the reference here: Disable Security - Open Distro Documentation