Why is a component not rendering inside another React component?

Question

React

I made a simple markup, began to break it into components.
But the components do not expand, they remain tags.
I can't understand what is the reason.
Here I took it to the sandbox (component btnOrderAction)

Answer 1

Well, why are you using ES6, and write class names with a small letter. Name your second class BtnOrderAction and be happy.