need help with the oekaki ;u;

[sel]

uuuughh so this has been eating away at me for a while, and i really would like to know the answer. how can you make the oekaki canvas vertical rather than horizontal? what i'm trying to draw right now really is better fit for a vertical canvas, and i've seen that it can be done, but i just. can't. figure. it. out.
it's probably something so obvious, too. please, if anyone knows the answer?

(sorry if this is the wrong place to ask, i couldn't find anywhere else to put this)

[Kaizoku]

You can use this tool to rotate the canvas. c: