app.js

// App.js
import React from 'react';
import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';

import LoginScreen from './screens/LoginScreen';
import RegisterScreen from './Screens/RegisterScreen';
import ContactsScreen from './src/screens/ContactsScreen';

const Stack = createStackNavigator();

export default function App() {
  return (
    <NavigationContainer>
    <Stack.Navigator initialRouteName="Login">
      <Stack.Screen 
        name="Login" 
        component={LoginScreen} 
        options={{ title: 'Login' }} 
      />
      <Stack.Screen 
        name="Register" 
        component={RegisterScreen} 
        options={{ title: 'Registro' }} 
      />

    <Stack.Screen 
        name="Contacts" 
        component={ContactsScreen} />

    </Stack.Navigator>
  </NavigationContainer>
);
}