Grafana Secure Login

I need help to secure grafana acesss.
I’m running grafana behind an Nginx Reverse Proxy and Anonymous login has been enabled at Grafana side and all graphs can be accessible through path and showing graphs through iframes which is working fine.
But now my problem is how can i make grafana secure so that iframed graph url can not be accessed outside the application??

like for example this is one graph iframe url:

which is working fine but I want that this URL can only be accessed through my other custom application not publicly.

can anyone please suggest me better approach to handle this ??

I can’t use Auth Proxy because I do not want to create a user in Grafana. for that, I’ve another mechanism to authenticate the users.