How to access animation editor system in C++

I’m going to create a function that customizes animation during runtime.
The goal is to create a new animation asset by displaying the character’s skeleton in the world and changing the data with mouse drag.
The first task is to make the default character’s skeleton tree appear in the world when I play, but honestly, I have no idea how to approach it.
Could you tell me the API?
I’m sorry for my poor English.
Below is a reference photo of the function that I want to implement.
The picture is 2D, but I want to implement it in 3D.
Thank you.