-Add prefab to your avatar.
-Constraint it to the desired location with parent constraint or others if you would like.
-Setup on ghost/buffer particle if you would like to summon multiple. (you can skip this step if you dont know what it is)
-Make an animation toggling the particle on and off to activate it.
-Allow it to stay on to the appropriate length that is required to let the particle play to its absolution (this is why i recommend learning how to use buffer particle!).
-Once youve done all that you should be good to go!