Create alert in Splunk to send events in Service Now

Hi, I am creating alert in Splunk And I want to send this as event in service now So I am using Service now add-on for Splunk. Under Trigger Actions i am using ServiceNow Event Integration but here I can see only 5 fields like Node,Type,Resource, Severity and description but I want to add more field like MetricName etc. So I can add more fields so that it will go to service now as event using this Event Generation trigger action. Added screenshot of trigger actions fields name-https://imgur.com/a/B4OX7eZ Thanks.