How to access device folder using react native file system - react-native

Question

I needed to fetch files from a custom folder I created with my rncamera roll app, I used react-native-fs to access the folder but was not able to get the files even though I correctly specified the folder name, but I get a Possible Unhandled Promise Rejection (id:7): Error: Folder does not exist. How can I access this folder?
Even when I removed the folder name RNFS.readDir(RNFS.ExternalStorageDirectoryPath) to check my console.log result I got the error "isFile is not a function".
What is wrong with this code and how do I correct them.
UNSAFE_componentWillMount() {
RNFS.readDir(RNFS.ExternalStorageDirectoryPath+"myApp Videos")
.then((result) => {
console.log('GOT RESULT', result);
return Promise.all([RNFS.stat(result[0].path), result[0].path]);
})
.then((statResult) => {
let videos = []
var allowedExtensions = /(\.avi|\.mp4|\.mov|\.wmv|\.avi)$/i;
statResult.forEach(item => {
if (item.isFile() && !allowedExtensions.exec(item.originalFilepath)) {
videos.push(item)
}
});
console.log(videos)
})
}
setIndex = (index) => {
if (index === this.state.index) {
index = null
}
this.setState({ index })
}
render() {
return (
<View style={styles.container}>
<ScrollView
contentContainerStyle = {styles.scrollview}
{
...this.state.videos && this.state.videos.length > 0 && this.state.videos.map((p, i) => {
const isSelected = i === this.state.index;
const divide = isSelected && this.share === true ? 1 : 3;
return(
<Video
source={{uri: videos}}
style={{opacity: i === this.state.index ? 0.5 : 1, width: width/divide, height: width/divide}}
key={i}
underlayColor='transparent'
onPress={() => this.setIndex(i)}
ref={ref => {
this.player = ref;
}} // Store reference
onError={this.videoError} // Callback when video cannot be loaded
/>
)
})
}
>
</ScrollView>
</View>
);
}