How to make a timer start when a key is press? and how to reset timer?

So i wanna do that whem i press R to reload, but i dont find the way to make it work, i also want to reset it, but with the same time i assigned to time.

public float reloadTime = 4;

void Update(){
if (Input.GetKeyDown(KeyCode.R))
{
reloadTime -= reloadTime * Time.deltaTime;
if (reloadTime <= 0)
{
Recargar();
}
anim.SetBool(“IsReloading”, true);
anim.SetBool(“IsShooting”, false);
}
else
{
anim.SetBool(“IsReloading”, false);
anim.SetBool(“IsIdle”, true);
}
}

private float timerStart, timeElapsed;
private bool timerStarted = false;
public float reloadTime = 4;

void Update()
{
if (Input.getKeyDown(KeyCode.R))  // Start/Reset timer
 {
 timerStart = Time.time;
 timerStarted = true;
 }
if (timerStarted == true)
 {
 timeElapsed = Time.time - timerStart;
 if (timeElapsed >= reloadTime)
  {
   // Do your animation ...
   timerStarted = false;
  }
 }
}