As of now, Krita's Popup Palette can only be toggled by an either a Keyboard Shortcut or a Canvas Shortcut. I suggest we add a toolbar action and a Touch Docker button for toggling Popup Palette, it will make life much easier for people whose stylus has no or just one button.

We already have a toolbar action called "Toggle popup palette with S-Pen" to do this. But for some reason, this action is labeled as S-Pen specific, and thus not available on desktop versions. It is just a button in the toolbar, though. I think maybe we can relabel it, and make it available on every platform?