How to use the leftg mouse as input unity code example

Example 1: left moust click unity

//Left mouse Click
if(Input.GetMouseButtonDown(0))

//Right Mouse Click
if(Input.GetMouseButtonDown(1))

//Scroll Wheel
if(Input.GetMouseButtonDown(2))

Example 2: GetMousebuttonDown unity

if (Input.GetMouseButtonDown(1))
//This is too stop spaming the gun