Move layers straight up or down with a locked axis?

In desktop Photoshop, when using the transform tool, you can hold shift to lock the movement axis of a layer so it only moves sideways or up and down, but I can't find and way to do this in Fresco unless it's aligned off the center line of the canvas. Is there a good way to do this already? Even if the nudge tool could do bigger steps, that could work too.