This component expects an ES6 environment, and so if you are using this in an app, you should drop in a polyfill library - it has been tested with babel-polyfill but core-js or es6-shim may also work.
The default export is a React Component, so you can simply import the component and use it within some JSX, like so:
import Sharebar from '@economist/component-sharebar'; return <Sharebar/>;
For more examples on usage, see
npm i -S @economist/component-sharebar