Variable with empty value in request will cause error

The following case will be error.

1. Added the params “username” ← First one
2. Added the params “username” ← Second one
3. For First one username params, I have assign the undefined variable, let’s say {{username}}
4. For Second one username params, I have assign the hardcode string “user_a”
5. I enable (check) the Second one, and disable (uncheck) the First one “username“ params.
6. I send an API request, the error occurred.


Expected:
The non defined variable or empty value should be ignore. just treat as null.
The same name params should be handled correctly