I tried to upload a image, but req.files is Null

my code is:

```
router.post('/hoteles/Agregar/Nuevo',(req,res) => {

    console.log(req.files);
    if (!req.files) return res.status(400).send('No files were uploaded.');

    var file = req.files.uploaded_image;
    var img_name=file.name;

    if(file.mimetype == "image/jpeg" ||file.mimetype == "image/png"||file.mimetype == "image/gif" ){
        file.mv('public/imgUpload/'+file.name,(err) => {
            if(err) return res.status(500).send(err); 

            var sql = 'INSERT INTO hotel(idHotel, nombreCadena, nombreHotel, calle, numero, estado, ciudad, estrellas, imagen_name) VALUES (NULL, ?, ?, ?, ?, ?, ?, ? ,?)';

            conn.query(sql,[nombreCadena, nombreHotel, calle, numero, estado, ciudad, estrellas, 'public/imgUpload/'+file.name],(err,result,field) => {
                if(err) return res.status(500).send(err);
                console.log('add ' + result.affectedRows + ' rows');
                res.redirect('/root/hoteles/Agregar/Nuevo');

            });
        });
    }
});

```

I'm using 
 const fileUpload = require('express-fileupload');

the output is 

'No files were uploaded.'