We need the person filling out the form to be able to download the PDF

We need the person filling out the form to be able to download the PDF to keep it. Is there capability to do this?

Are you referring to a copy of PDF submission or your own PDF file? 

In the autoresponder email, you can actually attach your own PDF File. You just need to upload the file in the Advanced tab of the autoresponder. Here's a guide: How-to-Attach-a-File-to-Autoresponder-Emails.

You can also enable the PDF attachment option so that the user who completed the form will receive a copy of the submission on a PDF file.

Autoresponder is the email alert that will be received by the user who completed the form. For more information, please check this guide: Setting-up-an-Autoresponder-Email.

Hope that helps. Thank you.