cannot find appended formdata in request body

[daton89]

i'm appending formdata fields to build the key, my client side function is:

function startUplaod() {
        const url = '/api/v1/files'
        const data = new FormData()

        values.files.forEach(file => {
            data.append(file.name, file)
        })

        data.append('_id', values._id)
        data.append('save_in', 'document')

        const config = {
                         // i've tried to set multipart form data but nothing changed
            // headers: {
            //  'content-type': 'multipart/form-data'
            // },
            onUploadProgress: function(progressEvent) {
                var percentCompleted = Math.round(
                    (progressEvent.loaded * 100) / progressEvent.total
                )
                console.log('percentCompleted =>', percentCompleted)
            }
        }
        Axios.post(url, data, config)
            .then(res => {
                console.log('res =>', res)
            })
            .catch(error => {
                console.log('error upload', error)
            })
    }

my server route:

const upload = multer({
            storage: multerS3({
                s3: s3,
                bucket: config.spaces.Bucket,
                acl: 'private',
                key: keyCb,
                metadata: createMetadata(req.user)
            })
        }).any()

    function keyCb(request, metaFile, cb) {

            const { save_in, _id } = request.body

            console.log('req.body =>', save_in, _id)

            if (!save_in || !_id)
                return cb(new Error('Required id and saveIn not found'))

            const key = save_in + _id + metaFile.originalname

            cb(null, Key)
        }

how can i find the data appended to the formData?

[daton89]

reading the source code of dropzone.js i've figured out that some servers like S3 expect the file to be the last parameter

so i've fixed appending other data before append the file.