Thank you for your answer. But as I have already written:
"But I don't get an [...]-option under "Values"."
Screenshot:
You need to click in the field, once... single click... to select the field. Then the button will show.
Staffyup, anywhere within that value field in that row, give it a single click and wait a second! you should see the ellipses appear at the far right side of the value column, and once you click on those three dots, you should gain access to the operation parameters. You can do this for any other operation other than a property checkpoint in order to parameterize that step as well.
