inside the API request panel on the right create a parameter for the parts you want the user to enter.
use that parameter inside the API by typing the dollar sign ($) and then choose the parameter you just created. This can be done in the header, body or even the url of the request.
For injecting value to the request:
POST request, in Circuit, right click to add the post request node you created. You will find an input node for the parameter you created
Get request: when using “Data builder” wrapper and choosing the GET request, you will see a field of the paramters you created. You can then connect that parameter in the data builder wrapper to a variable or parameter in that screen.
We will release soon a tutorial about building a chat app, and you will see that as well there