Facebook SDK for React Native

import { Settings } from 'react-native-fbsdk-next';

// Initialize SDK as early as possible
Settings.initializeSDK();

import { LoginButton, AccessToken } from 'react-native-fbsdk-next';

<LoginButton
  onLoginFinished={(error, result) => {
    if (error) {
      console.log("Login error: " + error);
    } else if (result.isCancelled) {
      console.log("Login cancelled");
    } else {
      AccessToken.getCurrentAccessToken().then(data => {
        console.log("Access token: " + data.accessToken);
      });
    }
  }}
/>