How can i Create Alert when a service goes off with any service like firewalld and other service

i have set an alert rule when my service is turned off it will not sending alert and not come in fire state.what query and threshold i need to apply
Query that i am using mentioned below d check what i need to set threshold for this Query

{*name* =“node_systemd_unit_state”, instance=“xxxxx.x.xxx.x:9100”, job=“node_exporter”,
name=“clickhouse-server.service”, state=“active”, type=“notify”}