Why isn't my API connector grabbing Arbitrary text from a workflow?

Hi everyone, thank you for your time!

I can’t figure this out. I have my API connector configured to send a JSON code containing a prompt grabbed from one of my workflows to ChatGPT. By “grabbed”, I mean that I have a workflow when a button is clicked, and within that workflow, I’ve configured (or so I thought) a prompt with dynamic data that is sent to the API connector, inserted into the JSON code, and then submitted to ChatGPT. Here are some screenshots:


My understanding at this point is that I need to write something in the Value input field of the Body Parameters in the API connector. If this is true, what do I write here so that the prompt in my workflow is included in the JSON code? Or am I way off base?

Again, thank you for your time!