Confirgure list form with JSON

Hi there,

I'm having some trouble in conditionally displaying a text depending on if it's a new form or edit form.

The following piece of JSON (when on New form type)

* JSON for Header *
{
  "elmType": "div",
  "txtContent": "=if([$Title] == '', 'Create new item' ,[$Title])"
}

returns the message:

"Failure: Title was not found on the data object"

Is there a way to have this sort of condition? Or is there a better way of doing it? 

I know with Power Apps will achieve that but I can't use Power Apps.

Thanks!