Rule Input in API connection

Question

Hello everyone, 
 I'm just starting learning to work with Appian, I'm currently doing the Developer's Path. Today I encountered a problem that seems very simple. 
 I just can't add Rule Inputs while creating a connection to an API 
 
 I tried clicking in edit as an expression, but I'm just getting this

Thanls

Peter Lewis · Answer

When you say you can't add rule inputs, do you mean you are unable to create a new rule input variable or that you are unable to reference it in your expression? To the first issue, you should be able to add a rule input in the pane on the right side (it might be collapsed by default). To the second issue, you can reference a rule input using ri! in any expression.

Abhay Dalsaniya · Answer

First you need to add the rule input as shown below.