I only want to turn a specific iMessage chat into a book. Why do I have to create a full backup of my iPhone?

Unfortunately, it is not possible to export a specific iMessage chat from your iPhone. So, in the first step, you need to create a full backup of your iPhone on your computer. In the next step, you can then select the specific chat you want to upload to zapptales and turn it into a book. This means that you only upload the particular chat you want to print.