How to change duration loop in particle systems in ue4.22?

I am not able to find duration and duration loop in the particle edittor. Please explain in detail as i am an absolute beginner.

The default particle system in UE4 is called Cascade. You can find it’s documentation here: Cascade Particle Systems | Unreal Engine Documentation

There is also a new particle system called Niagara which you can enable and play around with it.

Settings which you are looking for are under the “Required” Details.