Displaying PDF in Confirmation Message
You can display the file name and link to your generated PDF in your Gravity Forms confirmation message using merge tags.
When editing a confirmation message, there will be a Fillable PDFs group at the bottom of the merge tag drop down. Every configured Fillable PDFs feed will have three merge tags available: one that displays a properly formatted link with the PDF URL and file name, one for only the file name, and one for only the PDF URL.