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.
I saw that you have already customized your Thank You page. To add link of your PDF file on Thank you page, mark the text "Click this link" and select Insert/Edit link option and add URL of your PDF File inside of URL field. After that click on OK button and Save Changes.
Hope this will help. Let us know of you need further assistance.