Cross Cluster Search

I am trying to configure cross cluster search within my ECK stack and I am having a hard time with the documentation.

I am trying to configure with the API key related route and I am confused where to set the requisite settings on both remote and local clusters. I am running ECK and I am trying to connect Elastic on two separate kubernetes clusters. Where in my stackConfigPolicy would I put these settings? I have a shared secret for the CA certs so I am not worried about that/mounting them into the truststore. Can anyone help?