how to get the "incident_key" in pagerduty integration

[Anz14]

Hi Team, I have the stackstorm setup on Ubuntu VM for alert automation. I have integrated stackstorm with pagerduty.

Action chain workflow below:

---

chain:
-
name: "jenkins_disk_action"
ref: "jenkins.jenkins_disk_action"
parameters:
triggers: "{{ triggers }}"
on-success: "post_success_to_slack"
on-failure: "pagerduty_escalation"
-
name: "post_success_to_slack"
ref: "slack.post_message"
parameters:
channel: "#stackstorm-alerts"
message: "{{jenkins_disk_action.result}}"
-
name: "pagerduty_escalation"
ref: "pagerduty.incident.create.events_v1"
parameters:
service_key: "redacted"
description: "{{jenkins_disk_action.result}}"

How can I get the incident-key to avoid de-duplication of alert. How can I call the incident-key in the action -chain yaml