Using 7.8X version of kibana we are trying for ssl configuration using below link for guidence :[Elasticsearch Cluster Security - TLS, SSL & CERTUTIL Certificates]
But while generating CA Certificate using below command facing error as mentioned below at end :
bin/elasticsearch-certutil cert --silent --pem --in config/certificates/instances.yml -out /certs/bundle.zip
ERROR: Must specify either --ca or --ca-cert/--ca-key or --self-signed, with exit code 64