when app is running the only thing that is displayed is a blank white screen :- React Native

I have created an app on React Native , I have been stuck in one place from past week . When the app is initialized the only thing that is seen is blank white screen all the time I have changed ""div"" to ""view"" as someone suggested but still it gives the same output . Please provide a solution to it.
Best Regards

APP.JS

import React, {useEffect, useState} from 'react';
import {Button,View} from 'react-native';
import admob, {MaxAdContentRating} from '@react-native-firebase/admob';
import {
BannerAd,
BannerAdSize,
InterstitialAd,
AdEventType,
} from '@react-native-firebase/admob';
import firebase from 'firebase';
const BanneradUnitId = 'ca-app-pub-7184661797309439/5996869501';
const InterstetialadUnitId = ' ca-app-pub-7184661797309439/5399949611';
const interstitial = InterstitialAd.createForAdRequest(InterstetialadUnitId, {
requestNonPersonalizedAdsOnly: true,
keywords: ['fashion', 'clothing'],
});
const App = () => {
// ______________________ Request Configuration ___________________
useEffect(() => {
admob()
.setRequestConfiguration({
// Update all future requests suitable for parental guidance
maxAdContentRating: MaxAdContentRating.PG,
// Indicates that you want your content treated as child-directed for purposes of COPPA.
tagForChildDirectedTreatment: true,
// Indicates that you want the ad request to be handled in a
// manner suitable for users under the age of consent.
tagForUnderAgeOfConsent: true,
})
.then(() => {
// Request config successfully set!
});
firebase.initializeApp();
});
// ____________ Interstetial Ads setup ________________________
const [loaded, setLoaded] = useState(false);
useEffect(() => {
const eventListener = interstitial.onAdEvent((type) => {
if (type === AdEventType.LOADED) {
setLoaded(true);
}
});
// Start loading the interstitial straight away
interstitial.load();
// Unsubscribe from events on unmount
return () => {
eventListener();
};
}, []);
// No advert ready to show yet
if (!loaded) {
return null;
}
return (
<View className={styles.main}>
<h1>Hello World</h1>
<BannerAd
unitId={BanneradUnitId}
size={BannerAdSize.FULL_BANNER}
requestOptions={{
requestNonPersonalizedAdsOnly: true,
}}
/>
<BannerAd
unitId={BanneradUnitId}
size={BannerAdSize.FULL_BANNER}
requestOptions={{
requestNonPersonalizedAdsOnly: true,
}}
/>
<BannerAd
unitId={BanneradUnitId}
size={BannerAdSize.FULL_BANNER}
requestOptions={{
requestNonPersonalizedAdsOnly: true,
}}
/>
<BannerAd
unitId={BanneradUnitId}
size={BannerAdSize.FULL_BANNER}
requestOptions={{
requestNonPersonalizedAdsOnly: true,
}}
/>
<Button
title="Show Interstitial"
onPress={() => {
interstitial.show();
}}
/>
</View>
);
};
const styles = StyleSheet.create({
main: {
textAlign: 'center',
},
});
export default App;

build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.
// apply plugin: 'com.google.gms.google-services'  // Google Services plugin
buildscript {
ext {
buildToolsVersion = "29.0.2"
minSdkVersion = 16
compileSdkVersion = 29
targetSdkVersion = 29
}
repositories {
google()
jcenter()
}
dependencies {
classpath("com.android.tools.build:gradle:3.5.3")
// classpath 'com.google.gms:google-services:4.3.4'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
mavenLocal()
maven {
// All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
url("$rootDir/../node_modules/react-native/android")
}
maven {
// Android JSC is installed from npm
url("$rootDir/../node_modules/jsc-android/dist")
}
google()
jcenter()
maven { url 'https://www.jitpack.io' }

You firebase initialize config on useEffect doesn't have dependencies. Make sure to put the dependencies or just empty array for initialize purpose (onDidMount).

try change to this:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

useEffect(() => {
admob()
.setRequestConfiguration({
// Update all future requests suitable for parental guidance
maxAdContentRating: MaxAdContentRating.PG,
// Indicates that you want your content treated as child-directed for purposes of COPPA.
tagForChildDirectedTreatment: true,
// Indicates that you want the ad request to be handled in a
// manner suitable for users under the age of consent.
tagForUnderAgeOfConsent: true,
})
.then(() => {
// Request config successfully set!
});
firebase.initializeApp();
}, []);

<!-- end snippet -->