Styling the searchbar in wix's react-native-navigation v2

Question

I'm using the search bar in a react-native app (iOS 11+).

These are the options I gave to my screen:

options: {
    topBar: {
        title: {
            text: 'MyTitle',
            testID: TOP_APPS_ID,
        },
       searchBar: true,
       searchBarHiddenWhenScrolling: true,
    },
},

And it does display the search bar:

However, I would like to remove the bottom border it adds by default.

How can I achieve this? I tried setting "noBorder" to true in the topBar options but it still shows the border.