Jmeter event trigger payload update

https://github.com/keptn-sandbox/keptn-on-k3s/blob/ca985dbe5c9c8995ef1ea25aa7b60023a7b08405/performance.testing.triggered.placeholder.json#L21

I try to run with that expression to trigger a Jmeter execution but it didn't work. I have run it with this one sh.keptn.event.test.triggered and it works fine. So this expression might require an update 