...

import {Platform, StyleSheet, Text, View, NativeModules, NativeEventEmitter, Alert} from 'react-native';

// Import in the MyFiziq SDK plugin
var MyFiziq = NativeModules.RNMyFiziqSdk;
var MyFiziqEvent = new NativeEventEmitter(MyFiziq)

// Setup MyFiziq service
// NOTE: Replace the KEY, SECRET, and ENVIRONMENT strings with values given by MyFiziq
async function myfiziqSetup() {
  try {
    let result = await MyFiziq.mfzSdkSetup(
      "KEY", 
      "SECRET", 
      "ENVIRONMENT");
  } catch(e) {
    Alert.alert('Error', e,[{text: 'OK', onPress: () => console.log('OK Pressed')}],{cancelable: false});
  }
}

// Answer MyFiziq event requests
MyFiziqEvent.addListener('myfiziqGetAuthToken', (data) => {
  // Answer with idP service user authentication token, as per AWS Cognito OpenID mapping.
  // See: https://docs.aws.amazon.com/cognito/latest/developerguide/open-id.html
  // NOTE: null passed in this example, however OID token would be passed or null if user not logged in.
  MyFiziq.mfzSdkAnswerLogins(null, null);
});

...

type Props = {};
export default class App extends Component<Props> {

  // Initialize MyFiziq service on App startup via the App class Constructor.
  constructor(props) {
    super(props);
    myfiziqSetup();
  }

  render() {
    return (
      ...
    );
  }

  ...

}

...