React native Redirect authentication api
To get authorization code in react-native app, You need to set the custom Url scheme.
twitter has well documented guide to create it.
https://dev.twitter.com/cards/mobile/url-schemes
After creating the Url scheme. You need to set the redirect_uri as explained here in wp-oauth server's docs Step 2 and replace the created custom url of your app in redirect_uri.
This will redirect you to your app when oauth server's callback with the access token that you can use in your react-native application.