How to use the rn-fetch-blob.default.fs function in rn-fetch-blob

async function initialize(dispatch) {
	shimInit();

	// blobTest();

	Setting.setConstant('env', __DEV__ ? 'dev' : 'prod');
	Setting.setConstant('appId', 'net.cozic.joplin-mobile');
	Setting.setConstant('appType', 'mobile');
	//Setting.setConstant('resourceDir', () => { return RNFetchBlob.fs.dirs.DocumentDir; });
	Setting.setConstant('resourceDir', RNFetchBlob.fs.dirs.DocumentDir);

	const logDatabase = new Database(new DatabaseDriverReactNative());
	await logDatabase.open({ name: 'log.sqlite' });
	await logDatabase.exec(Logger.databaseCreateTableSql());

	const mainLogger = new Logger();
	mainLogger.addTarget('database', { database: logDatabase, source: 'm' });
	mainLogger.setLevel(Logger.LEVEL_INFO);
	
	if (Setting.value('env') == 'dev') {
		mainLogger.addTarget('console');
		mainLogger.setLevel(Logger.LEVEL_DEBUG);
	}

	reg.setLogger(mainLogger);
	reg.setShowErrorMessageBoxHandler((message) => { alert(message) });

async function initialize(dispatch) {
	shimInit();

	Setting.setConstant('env', __DEV__ ? 'dev' : 'prod');
	Setting.setConstant('appId', 'net.cozic.joplin-mobile');
	Setting.setConstant('appType', 'mobile');
	Setting.setConstant('resourceDir', RNFetchBlob.fs.dirs.DocumentDir);

	const logDatabase = new Database(new DatabaseDriverReactNative());
	await logDatabase.open({ name: 'log.sqlite' });
	await logDatabase.exec(Logger.databaseCreateTableSql());

	const mainLogger = new Logger();
	mainLogger.addTarget('database', { database: logDatabase, source: 'm' });
	mainLogger.setLevel(Logger.LEVEL_INFO);

	if (Setting.value('env') == 'dev') {
		mainLogger.addTarget('console');
		mainLogger.setLevel(Logger.LEVEL_DEBUG);
	}

	reg.setLogger(mainLogger);
	reg.setShowErrorMessageBoxHandler((message) => { alert(message); });

shim.fetchBlob = async function(url, options) {
		if (!options || !options.path) throw new Error('fetchBlob: target file path is missing');

		let headers = options.headers ? options.headers : {};
		let method = options.method ? options.method : 'GET';
		const overwrite = 'overwrite' in options ? options.overwrite : true;

		let dirs = RNFetchBlob.fs.dirs;
		let localFilePath = options.path;
		if (localFilePath.indexOf('/') !== 0) localFilePath = dirs.DocumentDir + '/' + localFilePath;

		if (!overwrite) {
			if (await shim.fsDriver().exists(localFilePath)) {
				return { ok: true };
			}
		}

		delete options.path;
		delete options.overwrite;

		const doFetchBlob = () => {
			return RNFetchBlob.config({
				path: localFilePath,
			}).fetch(method, url, headers);