objects are not valid as react child

[yashimaskara]

const MyAccountfunc= async ({navigation})=>{
let user = await AsyncStorage.getItem('user'); //it is showing error here
alert(user); //my user contains one mail
if(user==null)
{
alert('Login first')
navigation.navigate('Login')

}
else{
alert('done')
navigation.navigate('MyAccount')

}
return null
}

const DrawerNavigation = createDrawerNavigator(

{

  "Home": App,
  "My Account": MyAccountfunc,
  "Order History": OrderHistory,
  "About us": Aboutus,
  "Contact us": Contactus,
  "Logout": LogoutFunc

},
{
initialRouteName: "Home",
contentOptions: {
activeTintColor: "red"
}
}
);

export default createAppContainer(DrawerNavigation);