Fancy Forms with Nintex

I have a Flexi Task running on a list Item, with Delegation and everything is fine. Further when the Flexi task gets status User input needed a Task User input will start with the question forwarded, naturally delegation is activated. Everything work fine and as expected when using SharePoint Forms.

After all the Tests, I started building the Nintex Forms. In the Flexi Task I could still use the delegation functionality. Coming to the user input Task I could not find any delegation link in the Form nor did I find anything similar to delegation in the toolbar!

Am I missing something? Should I add any extra Tools to get that functionality? I just want to allow Delegation in User input Tasks.

Does anybody has a clue?