@f26227279 if you have security enabled in Kibana/Elasticsearch, users will always have to login to be able to use Kibana/Elasticsearch, even if Kibana is in an iframe.
If you'd like to embed a secured instance of Kibana in an iframe and not require users to login, you can create a user that has read-only access to Kibana and put a reverse-proxy in-front of Kibana that provides the username/password through Basic Auth header as discussed here