Edit poly shape how to move a point in x, y or z axis?

how do i change the axis of the dragged point … so i have a the shape of a river i have a point on that river… how do i change it from xy dragging to xz dragging… i.e. upwards and downwards for a point in the shape rather than left and right?

i used the package manager to update to 4… then I clicked on another mesh and suddenly all the handles appeared and probuilder kicked into life… all a bit odd… version control in unity is a bit of a nightmare all round.