BVHLoader and GLTF does not match

I created a cube in blender with 2 bones
And then I export the cube to .glb
The animation, I export to .bvh
When i load the glb file, the skeleton now has 2 bones, but in bvh, there are 3 bones
I want to add the END_SITE to the skeleton in gltf like bvh, what should I do ?

Are you saying you need an additional bone “added” to represent the length of the last bone shown in Blender? You may need to file a bug on the glTF Blender Exporter.

There are only two bones shown in Blender, also. If the fact that the BVH export appends a third bone is helpful to you, you could just manually add a third bone in Blender?

Currently, that is the way I choosed to show bones, but when the skeleton is more complex. I think I will modify the SkeletonHelper