In this unreal engine 5.3 Niagara Fluids tutorial we emit volumetric smoke and fire out of an animated character. This works for Mixamo animations too.
https://dev.epicgames.com/community/learning/tutorials/nPJJ/niagara-fluids-tutorial-character-on-fire-simulation-skeletal-mesh-vfx-in-unreal-engine-5-3