How can I match hand joints to smplx joint?

Thanks for sharing great project!

I'm studying alone in 3d Human field and less information that I have currently.
I want to apply your hand model to my smplx model

Could I simply use pred_hand_pose in pred_hand_list to input into smplx model's fro parameters in my project? or do I need to change the rotation(wrist global rotation)?

frankmocap/handmocap/hand_mocap_api.py

Line 228 in bb05b85

return pred_output_list

In this project I have 21 hand positions, but to get smplx output I need to input 15 joints for each hand, I don't know how to do it well.

frankmocap/integration/copy_and_paste.py

Line 134 in bb05b85

smplx_output = smplx_model(

So, How can correspondence between the hand joint points and the smplx model? and where are the other 6 parts used? only for 3d rendering?

Another question is
hand_pose shape is (1,45) but I want to convert the rotation matrix from rotation 6d to (n,Joints,3,3) format. I would appreciate it if you could tell me how to solve it