Running Grafana behind a web proxy - Sending Pushover notifications

I searched for this but couldn’t find information.

I have to run Grafana on a Linux server with limited access to internet.
For web (port 80, 443) I need to use a proxy.
System default proxy settings let me update or install plugins.

However, when I test notification channel Pushover it says message is sent but in fact there’s no traffic going to my proxy.
Is the Pushover code not using system proxy ?

Btw, server can not handle DNS queries (no nameserver set) itself. So all queries must go through the proxy.

Any ideas ?

nevermind, I figured out that Grafana uses system proxy. I just have to set it before running grafana.