Login to your organization's Panopto server.
Navigate to the folder that your session is located in. Once you are in the folder, you will see all recorded sessions. Locate the session you would like to upload a PDF to and hover over it and click "Settings":
Once in settings, click "Streams" from menu. At the bottom of the menu you can click "Choose File" and you can select the PDF document you would like to upload. Once you have selected the correct PDF file, click "Open".
Click the "Upload PDF" button and your PDF document will be uploaded to the session.