To add highlights to the page:

1. Click the "Highlight On" button and you will see your mouse cursor changed to a "Highlight Pen" cursor.

2. Drag and draw the highlight area on the page.
After adding the highlight area, you can click the on the highlight area and a note box will be shown for you to enter some notes. In the note box, you can input text about the highlight and change the default color of highlight by clicking the "Color box"

To exit from highlight mode, please click "Highlight Off" .