To backup WhatsApp on your iPhone to a PDF file, follow these steps:
- Install and launch TouchCopy on your PC or Mac.
- Connect your iPhone to your computer using a USB cable.
- In TouchCopy, go to the "Messages" section.
- On PC, click the "WhatsApp" tab under Messages. On Mac, scroll through your conversations until you find your WhatsApp chats.
- Select the WhatsApp chat you want to back up and click "Save as PDF." Your messages, including images, will be saved in the PDF file.
For detailed instructions on how to copy messages from WhatsApp to your PC in PDF format, please see this support article...
How to copy WhatsApp Messages from iPhone to your computer