React Native Dark Mode

I am creating an app with React Native Paper with the Expo CLI. For some reason, I am unable to get dark mode to work!

App.js

import React from "react";
import { Text, View, SafeAreaView } from "react-native";
import {
  Provider as PaperProvider,
  DarkTheme,
  DefaultTheme,
} from "react-native-paper";
import { NavigationContainer } from "@react-navigation/native";
import Splash from "./views/Splash";
import BottomNav from "./routing/BottomNav";

const theme = {
  ...DefaultTheme,
  dark: true,
  mode: "adaptive",
  roundness: 5,
  colors: {
    ...DefaultTheme.colors,
    primary: "#ffffff",
    background: "#000000",
  },
};

export default function App() {
  return (
    <PaperProvider theme={theme}>
      <NavigationContainer>
        <BottomNav />
      </NavigationContainer>
    </PaperProvider>
  );
}

Would really appreciate if someone could give some suggestions!

Got same problem while running app on web browser