How to Draw/ Highlight on your project
To draw/ highlight on your project, select Annotate.
You can then select between Pen, which can be used to draw on the file. You can also select the colour of the pen and the stroke size to change the pen tip size.
You can also click Highlighter, the middle icon, to highlight on your project. When selected another option for Opacity will appear, if you want to change how "see through" the highlighting is.