TypeError: Cannot read property 'RNFSFileTypeRegular' of null

Hello,

I have followed the instructions in the " Usage (Android)" section , then I inserted in my App.js, in the App function, these two lines:

```
const App: () => Node = () => {
var RNFS = require('react-native-fs');
var path = RNFS.DocumentDirectoryPath + '/test.txt';
....
```

but when I run:

`npx react-native start`

I get

`TypeError: Cannot read property 'RNFSFileTypeRegular' of null, js engine: hermes`

I really don't know what to do, any lead ?

Thanks a lot