The Set Text Of Text Field behavior replaces the content of a form’s text field with the content you specify.
You can embed any valid JavaScript function call, property, global variable, or other expression in the text. To embed a JavaScript expression, place it inside braces ({}). To display a brace, precede it with a backslash (\{).
Example:
The URL for this page is {window.location}, and today is {new Date()}.