Garafana Alert not avaliable

Dear community

I use Grafana v8.0.6 and I make an alert for my clickhouse dataflow to avoid it cutoff.

My data sourse from clickhouse(running in k8s,centos7),I make a timeseries table to show the dataflow from CK,and make an alert.

My alert is not avaliable sometime, it can’t trans Ok to alerting and make a call.

Alerting should be avaliable.
Here’s the SQL and alert configure.