The Pen is selected by default. Just click the tool and start drawing on the board.

To switch to the highlighter, click the highlighter icon. Your strokes will appear with lighter opacity.

You can adjust color and thickness using the menu that appears after selecting either tool.

Use the color picker at the end to choose any custom color you like.
​

Select the Eraser tool. The eraser only deletes scribbles from the pen or highlighter.
​