Custom Goat Horn Sound Files & Folder Structure

I've only been able to find one YouTube video that discusses how to add a custom sound to goat horns. But the video only discusses how to redirect to a different Minecraft sound and even then he says it only works some of the times and doesn't seem to properly troubleshoot it.
https://www.youtube.com/watch?v=GzxZFkloAoo&t=316s
Could someone help me with the folder set up and the jsons I need for this?