App2.js

import * as React from 'react';
import { Text, Image, View, StyleSheet, Alert } from 'react-native';
import { Button, Avatar, Badge, withBadge } from 'react-native-elements';
import Icon from 'react-native-vector-icons/FontAwesome';

export default class App extends React.Component {
    render() {
        return (
            <View>
                <View
                    style={{
                    backgroundColor: '#f5f5f5',
                    padding: 140,
                    alignSelf: 'center'
                }}>
                <Image source={{uri: 'https://raw.githubusercontent.com/zold-io/zold.github.io/master/images/logo-blue.png'}} style={{width: 128, height: 128, marginBottom: 20}} />
                  <Text style={{
                    alignSelf: 'center',
                    width: 300,
                    marginBottom: 20
                  }}>An Experimental Non-Blockchain Cryptocurrency for Fast Micro Payments.</Text>
                  <Button
                      onPress={this._authGithub}
                      buttonStyle={{
                          backgroundColor: "rgb(55,57,55)",
                          height: 45,
                          width: 130,
                          borderColor: "transparent",
                          borderWidth: 0,
                          borderRadius: 5
                      }}
                      title='Sign-in'
                  />
                  <Text style={{
                      alignSelf: 'center',
                      width: 300,
                      color: '#afafaf',
                      marginTop: 120
                  }}>© 2019 0.11.3</Text>
                </View>
            </View>
        );
    }

    _authGithub = async () => {
        try {
            console.log("try");
            let result = await authGithub();
            this.setState({githubToken: result});
        } catch(e) {
            console.log(e.message);
            this.setState({error: JSON.stringify(e)});
        }
    }
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: '#fff',
    },
    contentContainer: {
        padding: 30,
    },
    button: {
        marginTop: 20,
        padding: 20,
        backgroundColor: '#eee',
    },
    result: {
        marginTop: 20,
    },
});