How do I register sound keyframe?

I'm using MCreator 2024.4 with Geckolib and Geckolib Blockbench. 
I see the Animate Effect in Blockbench and used it to add in sounds for my entity
Then I exported the animation along with the model and imported them in MCreator
Then I started the build and saw this line in the Console: "Sound Keyframe found for [MyEntity] -> movement, but no keyframe handler registered"
How do I register the sound keyframe?

I notice there is a geckolib github that instruct on how to make the soundkeyframehandler but I can't seem to edit the code in MCreator.

Here's the Github link: https://github.com/bernie-g/geckolib/wiki/Keyframe-Triggers-(Geckolib4)