Elasticstack security

I am using a basic license and trying to enable security on a single node ELK cluster . to enable security i have added the below lines in elasticsearch.yml

xpack.security.enabled: true
discovery.type: single-node

In kibana.yml i have enabled the following lines

elasticsearch.username: "kibana_system"
elasticsearch.password: "pass"

but i am getting the below error in kibana log and the UI is not accessible

[security_exception]: missing authentication credentials for REST request [/_nodes?filter_path=nodes.*.version%2Cnodes.*.http.publish_address%2Cnodes.*.ip]"}

I have tried using the below credentials in kibana.yml but then also i am getting the same error:

xpack.monitoring.elasticsearch.username: "kibana_system"
xpack.monitoring.elasticsearch.password: "kibanapassword"

Any help on the above will be really great ..

You need to first set the password for the builtin users ( see here ), as kibana_system is a builtin user. Then you'd need to add that password as elasticsearch.password in your kibana.yml.