I seed to show Bottom Tab Navigator in App but it does not show up.

const MainTabs = () => {
  return (
    
    <Tab.Navigator>
      <Tab.Screen name="Home" component={HomeScreen} />
      <Tab.Screen name="Profile" component={ProfileScreen} />
      <Tab.Screen name="Settings" component={SettingsScreen} />
    </Tab.Navigator>
  );
};

const App = () => {
  return (
    <>
    <NavigationContainer>
      <Stack.Navigator initialRouteName="Login">
        <Stack.Screen name="Home" component={HomeScreen} options={{ headerShown: true }} />
        <Stack.Screen name="Login" component={LoginScreen} options={{ headerShown: true }} />
        <Stack.Screen name="Register" component={RegisterScreen} options={{ headerShown: true }} />
        <Stack.Screen name="MainTabs" component={MainTabs} options={{ headerShown: false }} />
      </Stack.Navigator>
    </NavigationContainer>

       </>
  );
};

Can you tell me what am I doing wrong ?