We have set up an on-call schedule in Jira Service Management and would like to notify our users whenever the on-call person changes (either due to the schedule or if someone manually takes the role in JSM). I have tried setting up a trigger, but I cannot get {{oncall}} as a smart value in any of the fields. I'll have to get the associated ID to satisfy GDPR requirements, presumably through something like {{oncall.accountId}}, but I need the field value to watch. Thus far, the documentation has failed me. All I want to do is trigger a Slack message that says "{{oncall.responder}} is now the on-call engineer." in one of my Slack channels.