What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
As far as I understand from your question, you want to upload a pdf file to preview it on your form. You can easily achieve this by using the widget called "PDF Embedder" Widget.
To do that,
1) Open the "Widgets" tab and search for PDF Embedder.
2) On the following widget settings window, define the PDF URL and check "Attach to Submissions" check box, if you want to add this file to your "Notification" or "Autoresponder" email.
If you refer something else in your thread, please let us know.