How do I get http headers in React.js

I've made a request to a React page, and I need to get the headers from the request.

I call the page via the URL:

http://localhost/dashboard

and I set headers, for example authcode=1234.

I then load the page with this route:

<Route path="dashboard" name="dashboard" component={Dashboard} onEnter={requireAuth}></Route>

is there something like this.props.header, I can call in the page constructor?