let me try to understand your setup and correct me if i have wrong assumptions in there:
you have a RKE cluster and deployed sonarqube in there (btw you are 2 patch releases behind the latest LTS release). now you are trying to display sonarqube in an iframe as part of a broader dashboard, resulting in the screenshot you posted. did i get that right?
i don’t think there is a easy way to configure the X-Frame-Options currently as they are hardcoded into sonarqube. What you could do is to configure a reverse proxy in front of sonarqube to hide the original X-Frame-Options from the request (option proxy_hide_header 'x-frame-options'; for nginx for example).
while i would not recommend you to do so for security reasons, it might solve your use case.