Slack templating Title

Hello,

I would like to change the title of the messages sent in Slack.
Here is my template :

[{{ .Status | toUpper }}: {{ if eq .Status "firing" }}{{ .Alerts.Firing | len }}{{ else if eq .Status "resolved" }}{{.Alerts.Resolved | len }}{{ end }}] [{{ .CommonLabels.type | toUpper }}] [{{ .CommonLabels.severity | toUpper }}] {{ .CommonLabels.alertname }}

I can’t get AlertName to work, I tried

{{ .Name }}
{{ .Labels.alertname  }}
{{ .CommonLabels.alertname }}

my labels are :
type: infra
severity: critical

The results:
[FIRING: 1] [INFRA] [CRITICAL]

Have you an idea ?

Try adding a key value alertname = cpu high under Labs for ex