Actually, the hierarchy is under root in the mesh:
So, “skeleton_male” should be renamed “skeleton_male.001” and “root” “RL_BoneRoot” to match the names of the animation hierarchy.
Once it is done, you can create a new animation group by retargeting the transform nodes to the ones of the mesh:
There are still some nodes that don’t exist in the mesh (see the console log of the browser): for these ones, the animations are simply not created.