Update dictionary in if() function

Question

I am trying to insert data in dictionary in if condition and it shows reaction tree in output. I am new to appian please help me with this.

Harshmodi · Answer

Hello, 
 I believe you're attempting to use the a!save() function within an expression rule.The a!save() function requires saveInto parameters that are available in the interface components. Additionally, updating variable values directly in an expression rule is not possible. Such modifications can only be made within an interface, not within an expression rule. 
 https://docs.appian.com/suite/help/23.4/fnc_evaluation_save.html