Heroku Buildpack that that permits use of pdf-fill-form >= 3. It does the following:
Special thanks to @bdbau for suggesting the pdfinput repo and the
pdfinput repo itself.
Add this buildpack before
node.js. You could just add it to the top using:
heroku buildpacks:add --index 1 https://github.com/aatishnn/heroku-buildpack-pdfinput
Copy the snippet above into CLI.