How to properly set up Alert in Grafana?

Question

CentOS

How to correctly set an alert in graphana so that, for example, when bits send falls to 0 or just to 0, an alert arrives that doesn’t work, falls to 0.
It’s like this for me, but it doesn’t work (
chart 1.


Chart 2.


With these settings shows that everything is a class, although now everything hangs at 0.