Newcomer asking for a help

My situation is that I have downloaded pokemon models and imported them. They have all the bones there, those seems to be fk-joined but when I export it to my unity-based game as a mod, they lose all the fk joints. What…How… How can I make them permanent or what’s the search term for this subject?

Maybe search for: blender howto export rig to unity in your favorite search engine??