Alert manager triggers web-hook repeatedly for same alert

I have configured the alert manager rule to trigger alert when Prometheus metric changes from 0 to 1 It triggers a webhook alert upon metric changed from 0 to 1 But the alert manager keeps triggering webhook, duplicate alerts for the same metric change.

Is there a config to prevent silencing further alerts from the alert manager?

below is my alertmanager config

global:
  resolve_timeout: 15m
  http_config: {}
  smtp_hello: localhost
  smtp_require_tls: true
route:
  receiver: web.hook
  group_by:
  - ccu_code
receivers:
- name: web.hook
  webhook_configs:
  - send_resolved: true
    http_config: {}
    url: http://service:8080/alarms
    max_alerts: 0
templates: []

You can try changing the max_alerts field to 1 if you just want it to fire once.