Problem with 3D pivot

So, I have a problem with Unity joints and pivots in 3d. I want to make a hand ragdoll, but the ragdoll creator doesn't work for hands, so I decided to make it myself. I messed around with hinge joints, and character joints, and all kinds of joints, but nothing looked right! I looked in the scene view and found the problem... It was rotating by the middle of the finger! I tried changing the pivot, but the two main methods don't work here! With Pro Builder, my model seems to be incompatible with it, maybe because I made it with Blender. With the child and parent method, since I'm using joints, the parent object interferes with the RigidBody's and doesn't work. Help, please?