How to "Drag using the Left Mouse Button"

How to "drag using the left mouse button",

also known as "left mouse button click and hold without releasing."

On a Chromebook with no external mouse present, if you need to 'grab' a scroll bar and slide it up or down, left or right, etc. ...

For a right handed person using, a right handed mouse, just hold your left hand index finger on the mouse pad without releasing, then with your right hand index finger slide up or down, left or right, etc.