req.uploadFileName is undefined.
console.log('Upload file...' + req.file); //undefined
console.log('Upload file...' + req.files); //undefined
console.log('Upload uploadFileName...' + req.uploadFileName); //undefined
console.log('Upload  body' + req.body) //undefined

export const uploadFile = (req, res, next) => {
    console.log('Upload file...' + req.file);
    console.log('Upload file...' + req.files);
    console.log('Upload uploadFileName...' + req.uploadFileName);
    console.log('Upload  body' + req.body);

    let file = req.uploadFileName;
    console.log('Upload fileName' + req.body.uploadFileName);;
    if (file) {
        uploadImageToStorage(file).then((fileURL) => {
            res.json({
                status: 'success',
                fileURL: fileURL
            });
        }).catch((error) => {
            console.error(error);
            next('failed to upload file ', error)
        });
    } else {
        console.error('failed to upload file ', file);
        next('failed to upload file ', file)
    }
};

export const getUpload = () => {
    // no larger than 5mb, you can change as needed.
    const multer = Multer({
        storage: Multer.memoryStorage(),
        limits: {
            fileSize: 5 * 1024 * 1024;
        }

    });
    return multer.single('uploadFileName')
}