Making A Particle Play when KeyPress And Particle Stop in 3 sec.

hello!
im not good at all at scripting…
I am making a Simulation Simulator (3 Simulators in 1)

and in my rock simulator, I want it to play a particle when I press “R” and then after 3 seconds, it stops… I need a script for that… and I wanna see how to use it to make it work,

I already made it so when you press “R” it plays “WWE The Rock theme song” (I made it 3 Sec. Short)

if (Input.GetKeyDown (KeyCode.R))
{
ParticleSystem.enableEmission = true;
}
else
{
ParticleSystem.enableEmission = false;
}
do this and in the inspector set the particle system’s duration to 3.