Template the content of a Slack message

hi, I am using grafana for monitoring and i send alert to slack app. I want to create Template for a Slack message. I can find template the content of a Slack message to contain a description of all firing and resolved alerts, including their labels, annotations, Silence URL and Dashboard URL. {{ .SilenceURL }}, {{ .DashboardURL }} is working . But not this "{{ .SourceURL }} " template variable. I want to add slack messages my alert rules source url. like this ((http://10…:…/alerting/grafana/7c6fb001527969fa/view?orgId=1)