Custom meta human in 5.6.1, the skeleton mesh is twisted. How do I fix it?

Hello, I’m a Newbie student preparing for a project as a meta human. While studying this time, I created a custom character as a meta human using Unreal 5.6.1.
However, maybe the skeleton mesh is twisted, but the arm remains twisted.

I want to know how to modify the skeleton of the meta human.

There are quite a few problems with facial expressions, but I’m referring to some videos on YouTube.

I couldn’t find a way to fix Meta Human’s skeleton no matter how much I looked, so I’ve come this far.
Currently, I can use it in parallel with Metahuman for maya.

Please give me some advice. Thank you.