In the 3D viewport, search for “Bake Action”, set the desired frame range and options, then click on “OK” to bake.
Note: Make sure the bones don’t have any keyframes on them, else it won’t work. Also, you may have to zero out the bones first if things go a bit crazy.
I don’t know about the automatic keyframing method. Couldn’t get it working either.
Our studio is creating some AR apps and I’ve integrated Jiggle Bones on some characters, and it’s fantastic.
Above is an example where it was used. The character’s hair, and the hair on the horse’s mane and tail are Jiggle Bones. They did require some keyframe fixing afterwards (The horse’s tail required quite a bit of work actually), but all in all, they save a lot of time and look pretty great.