Linux Find Mouse Button
You are Welcome! The Tutorial Shows You Step-by-Step How to Find the Mouse Device Button ID in GNU/Linux Distributions.
And the Xev Linux Tool creates a Window and then asks the X server to Send it Events whenever anything Happens to the window (such as it being Moved, Resized, Typed in, Clicked in, etc.).
Finally, the Guide includes detailed instruction on How to Map the Mouse Button on Ubuntu Desktop.