Vertical stairs and skeletal animation, can you give me an idea?

Question

C++ / C#

There is a humanoid, with skeletal animation and a charter. In general, everything is as it should be. But the ladder is a big problem. I tried to go when the trigger was lost - it does not let me. I also wanted to find an animation for climbing a ladder, but an unusual one (there is already one) but with a passage further. But I didn't find any. Suggest an idea. what is worth trying?