How to lock transform like this

This model made by Polygon Blacksmith is perfectly fine and they’re animating well, that’s why I’m trying to use this as my guide. I’m currently making my first model with animation, but when I animate it the gameobject transform of my model moves, unlike to this model. How can I lock the transform of my model? is it in the model software I used or on how I imported it in Unity?

Look closely on the Transform.
Here’s my guide: https://giphy.com/gifs/11VQoqSdHzvKWA/html5

Up for this