Webmerge for Ninja Forms 

ninjaforms.com/extensions/webmerge/
Do you wish users could populate documents directly from your WordPress website?
With WebMerge and Ninja Forms, now you can.
Create a form, map the fields to the document you’ve uploaded, and publish your form.
Any user can now populate the document directly from that form, and it will land in your selected destination as soon as they hit submit.
Populating digital documents from WordPress has never been easier. Download WebMerge for Ninja Forms today!
*Utilized music arrangements composed by Josh Cook via: joshthemusician.com