How to bind selection from dropdown input form to variable used in scriptable task in Orchestrator?

Hello,

I am quite new to VMWare orchestrator, and I try to perform a task that seems simple, but which is driving me crazy because I do not seem to figure out how to do it from the documentation: I have created a dropdown-element using two constant String Values to select from. All I want to do is to bind the value the user selected (or the dropdown index alternatively) to a variable, which I can pass to a scriptable task to be used there for further processing.

I already figured out that if you create a simple Input variable, then it automatically creates an input textbox, but nothing similar is available for a dropdown box. So how can selections from a dropdown element be bound to a variable?

Thanks!