I am making a web app with AFrame where users can create their own avatar using Ready Player Me avatars, and have their avatars do animations taken from mixamo.

I have downloaded from mixamo a full body avatar with RPM model. Then imported it to C4D and renamed all bone names to match RPM avatars, i.e. mixamoRigSpine => Spine. Then I loaded the model to AFRAME. Applied animation-mixer component. The character plays the animation correctly. Now I can't copy the animation to user's avatar. Copying animationClip doesn't work. Is there any tips that I am missing?

My avatar and user's avatar share the same structure as both of them came from RPM, and have the same bone names.