Your alert should have preview routing, where you can see which notification policy is catching your alert.
Unified (not old obsolete legacy) alert is event based - firing event generates event with labels and then based on labels you define which contact point will be triggered in notification policy - that’s complex, but powerful concept (but many people has a problem to understand it, so that simplified routing was also introduced), e.g. os=linux => send email to linux support group, priority=p1 => send text message to CTO, …
