I am currently learning Photoshop on my MacBook Pro and got to learn that a straight line can be drawn with brushes using the shift key. I don't have a graphic tablet, but I have an iPad Pro with an Apple Pencil. And I got to learn that the shift method of drawing a straight line isn't available on iPad Photoshop. Hence, I am writing this here to request for this feature. Hope others who need this feature vote for it.