What do you enter as the "host" while deploying a 3 node cluster and using elasticsearch_certutil http

I am having trouble getting the correct http certificate. I have deployed a 3 node cluster according to the config. mentioned in this elastic article - Encrypting communications in an Elasticsearch Docker Container | Elasticsearch Guide [7.13] | Elastic

The ssl/tls part here is done and it works fine. But now that I go for the Elastic Stack plus secured HTTPS traffic, i run the mentioned steps and do the necessary changes in the .yml file.
But on running the configuration i get the following errors:-

  1. Two keystore can not exist. ( one for ssl, one for http)

then after removing ssl as the keystore and keeping the http key
2. error","savedobjects-service"],"pid":951,"message":"Unable to retrieve version information from Elasticsearch nodes.
The kibana does not work with the http key (the cluster works at 30 % red status)

My last question is about this article - Set up basic security for the Elastic Stack plus secured HTTPS traffic | Elasticsearch Guide [7.13] | Elastic

in step 2(h) what should i enter as hostname? Is it the node es01,es02,es03 ?
( for ref. to my .yml file Encrypting communications in an Elasticsearch Docker Container | Elasticsearch Guide [7.13] | Elastic)