This article gives you an overview of how to use the PDF Editor and add editable fields to a PDF template. This provides you with an opportunity to add any custom data that can be added after PDF is generated. For example extra shipping information (truck number) or name and a signature on the PDF.
In order to do that:
Open editor (see here)
Create new or select an existing data field
Open the "advanced" tab in the right sidebar and select "Render as an editable Field"
4. Now when this PDF is generated from Katana it's possible to fill in the required text on the PDF.