How do I play a walking animation for a custom npc model whenever it's speed is not zero?

I'm using the .Running event for a humanoid, and it doesn't seem to work. Any work around so that the animation only plays when the npc is moving?

EDIT: I apologize, this was an issue with the code itself, I had a never ending while loop on top of the event function for the animation. The issue is resolved.

This was solved when I realized the issue was elsewhere. I had used the same method described in this post and I can confirm that this will work for even custom npc models

https://scriptinghelpers.org/questions/23797/playing-a-walk-animation-in-a-custom-character-updated-script