Insert variable into web service call

Hello all - 

I am attempting to call some web services to automate the update of chat bots and have been successful, but am wondering if there is a better, more streamlined way to do it. I am unable to insert variables into the request body and have to split everything up. I have tried using the Build String action as well as a Dictionary, both come through as empty.

Build String Action:

Dictionary Action:

Result in wf:

For now I am doing something like this:

var_body1 = {"startData": {"se_title": "

var_body2 = ","se_answer": "

var_body3 = "}}

So then I insert all 5 variables...

{Variable:var_body1}{CurrentItem:Title}{Variable:var_body2}{CurrentItem:Answer}{Variable:var_body3}

This works, but why do I have to jump through this many variables just to construct the body of a web service call? Imagine if I needed to insert 5 variables? 10? You see where I am going with this....

Is there something that I am overlooking in my syntax or something more "Nintex" specific" that I have to incorporate?

I was able to do this in NWC (with no issues), but if I attempt to hit the NWC end-point that I created, I run into the same issues (as I need to pass variables in the start data).

Thanks!