1. Enter reading page -> Tools;
2. Select between Highlight, Underline, Squiggly and Strikethrough on the toolbar;
3. You can change the color and opacity of the annotation on the side panel and add Note to comment;
4. To remove the annotation or edit the note, right click the annotation and select Delete or Note;
5. You can markup continuously until you tap the icon on the toolbar again to exit the annotation mode.