after enabling the whiteboard , and writing something on the screen
there is only one button to undo last action
it would make more sense if there is a “clear the whiteboard” button
as the space available on phones would allow you to write like one sentence by hand
Go to Settings > Appearance > App bar buttons and chnage the relevant settings there. If you set the clear whiteboard option to Always show, it’ll show up in the top bar. Let me know if that works.