This article explains three ways to sign a PDF file on a Mac: using your finger on the trackpad of your iPhone, or by scanning an image of your signature with your Mac's camera and saving it for future use.
How to Add a Signature to a PDF on Mac
The Preview app is a powerful macOS tool for editing many different types of documents. It’s also great for signing PDFs. Here’s how to use the trackpad to enter a signature.
Open the PDF file in Preview.
Click Show Markup Toolbar.
