How can i import animation from Motive to UE

I am trying to import Fbx files (simple animations) created in motive using the OptiTrack system to unreal but there is an issue with the root bone. I cannot do any retargeting because it would not let me import anything without selecting a skeleton, which I don’t have. I assumed unreal would have created one automatically, but in order to proceed with the importing process I need to choose one . I have already tried to add a root bone to my skeleton using blender, but then the animation would not play in ue

Any Suggestions¿