How do I hide the shadow under react-navigation headers?

Question

How do I hide the shadow under react-navigation headers?
They look like this.

Answer 1

I don't know how much this answer will value, but sharing my code to let you know that this worked for me for react-navigation version: 3.9.1

const AppNavigation = StackNavigator(
{
  FirstScreen,
},
{
 defaultNavigationOptions: {
  headerStyle: {
    elevation: 0, //for android
    shadowOpacity: 0, //for ios
    borderBottomWidth: 0, //for ios
  },
},
})