Grafana Notification policies label regex supporting

There are over 100 application with over 5000 servers.
Our application have similar pattern like the following

  1. app=FNA-CORE
  2. app=FNA-SYS
  3. app=FNA-APP

Notification policies will work if i setup multiple alert rules.
However, the grafana documentation did not state clearly.
I tried to define regex under labels on notification policies but seems failed.
app =~ FNA-(CORE|SYS|APP)
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