Grafana behind http proxy

[kkromkowski-GOD]

Hi,
Please forgive me if this is a trivial thing but I was not able to find a solution anywhere.

I am running the RKE2 cluster on which I have installed Prometheus-Stack with Grafana using Helm3 (45.30.0).
The thing is that all nodes are running behind http-proxy to reach the internet.
So when a Grafana tries to import a dashboard using ID it gets "Gateway Timeout".

How can I set the proxy so that it works only for Grafana? - No other service should be able to use it.