How to upload pdf to your form?

You could add the File Upload field to your form in order to allow the submitter to upload the file, you will find it under the Basic Fields section while in the Form Builder:

You could also change the file allowed types by following this guide: https://www.jotform.com/help/29-How-to-Change-the-Allowed-File-Types-Extensions-in-the-Upload-Field 

And this one will help you to change the default max upload size: https://www.jotform.com/help/33-Changing-the-upload-size-limit 

If you have any question, please let us know.