labels.alertname is not working about prometheus-config HOT 7 CLOSED

{% if customer %}Customer: `{{customer}}` {% endif %}

*[{{ status.capitalize() }}] {{ environment }} {{ severity.capitalize() }}*
{{ event | replace("_","\_") }} {{ resource.capitalize() }}

\`\`\`
{{ text }}
\`\`\`

{% if status == 'open' %}[Runbook](https://XXXX/display/NOCRUN/{{ event | replace("_","") }}){% endif %}

global:
  http_config:
    proxy_url: 'http://proxy:3128'
  smtp_smarthost: mysmtp
  smtp_from: mymail
  smtp_require_tls: false
  smtp_hello: prom
  smtp_auth_username: yyy
  smtp_auth_password: xxx

inhibit_rules:
  - source_match:
      severity: 'critical'
    target_match:
      severity: 'warning'
    # Apply inhibition if the alertname is the same.
    equal: ['alertname']

route:
  group_wait: 30s
  group_interval: 1m
  receiver: 'alerta'
  routes: 
    - receiver: 'alerta'
      continue: true
    - receiver: "infra-alert"
      match: 
        scope: infra
    - receiver: "system-alert"
      match: 
        scope: system

receivers:
  - name: "alerta"
    webhook_configs:
    - url: 'https://alerta.XXX/api/webhooks/prometheus?api-key=XXXX'
      send_resolved: true
  - name: "system-alert"
    email_configs:
      - to:  system-alert@XXX
        send_resolved: true 
  - name: "infra-alert"
    email_configs:
      - to:  infra-alert@XXX
        send_resolved: true 

....
rule_files:
  - rules/*.rules.yml
alerting:
  alert_relabel_configs:
    - target_label: environment
      source_labels: ['env']
  alertmanagers:
    - static_configs:
      - targets:
        - alertmanager:9093