prompt user in self-service x

Hello

I am new to self-service x so I am trying to figure out its limitations.

I can think of a few cases where the flow would require user interaction to take a decision, for example by asking the user to answer Yes/No through an input type "Prompt user".

I created a test flow and ran it but couldn't make it work. I got the error in OO central

Failed to complete: "Unsatisfied required input ..."

Is input type "prompt user" supported in self-service x?

Typically in OO Central a flow will stay on "Paused" status until the input is provided but here I saw it failed so I'm not sure if I did something wrong.

Thanks

Sergio