How to make an animation play on specials 3d models

Hi, my friend got a 3d model of a monster and got the animations from Mixamo and I tried to make an ai for it but because of the model, there is not root part, no humanoid, only an animation controller with an animator inside and a Mesh name reference_ with the bones inside to animate the model, but I don’t know how to make these animations work on an ai system.

The mesh and the children :