Add to OmniFocus: Due date + 3 weeks

Hi and thanks everybody for help.

I’m working on a workflow to choose a calendar event, add this to OmniFocus. This works. My problem is i want to set automatically the due date to today + 3 weeks. And this didn’t work. Is this possible?

The workflow is https://workflow.is/workflows/e0a222eefeef4da1a9816874aa5c9ae5

I want to change the parameter for due date like explained.

Thanks again.