Just a quick correction, pressing z in RAWTherapee will zoom the picture in to 1:1, but it doesn’t actually crop it. You have to use the crop tool to actually export a cropped image.
Thanks for the correction, @buddingphotographer. I realize I just gave the first half of information and left the cropping part unexplained. I was wrong to say that pressing ”z” would crop a picture at a 1:1 ratio, as it will only zoom it.