How to attach Slash VFX to the character slash animation

I would like to know how to attach VFX to a character animation;



In fact, I have done something now but the output is not so good, the Slash VFX and the animation not in-sync;

I have setup the character with this hierarchy:
Character
- VFX / Slash VFX
- Model with Humanoid Studio

And this is my workflow:
- Setup the Character model with the above hierarchy and VFX
- Duplicate the Humanoid Animation so that the animation can be modified
- Add a event to activate the Slash particle
- Tune the VFX position and rotation
- Testing the Play Mode

Attached the video of my work

Thanks
Ken