You can click anywhere on the document to add an annotation or use the marker tool on the right to drop a pin. You can enter a note into the text field on the grey toolbar at the bottom. This note will appear on your document. If you would like to remove your annotation, click the rubbish bin on the right to remove it.
Click the highlight tool on the right then drag and drop a box to highlight a section of your document.
Click the scribble tool on the right then click and hold to draw on your document.
Click 'Close' at any time to return to the folder view.
You might also find these articles helpful:
How to Share Annotations
Updated on: 29 / 07 / 2021