Gizmo transform tool problem

Hello,

I'm starting out with modeler and I'm having trouble using the gizmo (maybe I understand it wrong). I want to scale the object (sub tool) along the different axis, but I only have the grey dot to change scale. I've seen videos where there are gray dots on each axis to scale along the axis. Am I doing something wrong ? Or is there a another way to deform the object ?

Thanks !

François