1, find a piece of white paper (without any pattern) and sign your name.

2. Open the preview and select preferences.

3. The last Signature at the top of the preferences, select it and click Create Signature.

4. At this time, a camera window will pop up, aim your signature at the camera, and the camera preview window will have a blue line. Note that all your writing must be above the blue line. A preview of your signature will appear on the right. When you adjust to the right position, just choose to accept it.

5. At this point, in the PDF main window, click the "Edit" button, and a row of options will appear. Click the "Signature" option and select your signature from the drop-down box. A cross cursor will appear on the document and you can drag it.