Iirc grafana ~v8 had the ability to send pictures of graphs with alerts natively which was pretty nice, seems like v9 doesn't have that built in anymore.
Anyway I wrote also a post about my Grafana alerts, that are delivered to my as Pushover push notifications: https://giuliomagnifico.blog/tips/2022/12/12/Grafana-Pushove... (without the images, but with the panel ID/URL, so you have only to tap if you want to see the full graph)