How to use the animation plugin “ik rig” in the branch UE5-main?

Hi there, recently I founded the plugin named “ik rig” in the branch “UE5-main”. I tried to use it in my demo, but it’s so hard for me. I’ve tried reading the source code, but I still so confused. I’ve also tried searching for documents on google and I found nothing about it.
Does anybody know about this plugin? Is there any document or demo about the plugin?