Add on Prometheus - Grafana SMTP configuration

Hi all,
I want to use the Prometheus add on to monitor my microk8s cluster.
How can I configure the SMTP settings for alerting (notification channel) in Grafana?

“SMTP not configured, check your grafana.ini config file’s [smtp] section”

Thanks for your advice
Peter

Does anyone use the Grafana Addon?
How can I configure it?
Can someone tell me how can i set the SMTP Settings?
What is the best Praxis to configure a microk8s Addon?

Thanks for your advice
Peter