How to make a GameObject Prefab Animation Event, on an animation frame of character

Hi there! I am trying to get a gameobject prefab to ‘appear’ (be triggered) at a specific frame of an animation of a character. I learned that it is ‘Animation Event’ (on the animation itself) you must use to make ‘animation events’; so I opened the animation (in Animation window), clicked ‘add event’ at the desire frame, and then in ‘game object slot’, I added the desired prefab; but nothing happens, the prefab does not appear in the game at the frame - when the character plays this animation, no gameobject/prefab appears.

Now, I understand there must be some ‘signal’ to ‘get the prefab’ at that specific frame of the animation. I read that GameObject.SetActive…could be one… tried it does not work.
Invoke method, SetActive …or GetObject…the empty box fields say Int, Float, String…I’m not sure what is suppose to be the ‘right’ call to get the prefab at that frame (is it a string, bool…you must type there)…as a Animation Event.
Any help is greatly appreciated and thank you very much in advance.

PS: If you know, what would be the inverse…to make a gameobject prefab… disappear/turn off - at that frame.

That Object Slot defines where to send the signal. You should listen that signal from c# code and act on it.
You can check here : Unity - Scripting API: AnimationEvent
Also there is plenty of video tutorial on that topic. Just make a quick Google Search

I hope this answer helps. Have a great day