How to resize buttons with mouse?

Hello, obviously a Noob Que but surprisingly no answers anywhere for this on the internet -> How to resize buttons with just mouse to editing in scene view? As shown in other tutorials, I click on the button in the scene view and it shows the 4 blue corner dots and a blue central circle, but none of this responds to either of the mouse clicks (both right or left clicks) or any keyboard combos (viz Shift, Control or Alt). I am on Unity 2018.3.0f2 Personal and in Scene -> "Rect Tool" and I am trying to just resize a default button to a size of my wish. Pls help Thanks