aws-next.js file upload unsignedpost

gistfile1.ts

//client-side code 

const formik = useFormik({
        initialValues: {
            username: '',
            bio: '',
            img: ''
        },
        onSubmit: async (values) => {
            let data = new FormData();
            data.append("artist_name", values.username);
            data.append("bio", values.bio);
            data.append("file", values.img);
            data.append("admin_email", user.email);
            const res :any  = await createUnactivatedArtist(data);
            const { url, fields } = res.data;
            const file = values.img;


            console.log({ file })
            console.log({ fields })

            const uploadForm = new FormData();
            Object.entries({ ...fields, file }).forEach(([key, value]) => {
                //@ts-ignore
                 uploadForm.append(key, value);
              });

            const upload = await fetch(url, {
                method: 'POST',
                body: uploadForm,
            });
            
            if(upload.ok){
                console.log({ upload });
                console.log('upload successfull');
            } else {
                console.error('upload failed');
            }
            
        },
    })
    
    //backend api route 
    
    export default unactivatedArtistHandler
    .get(async (req: NextApiRequest, res: NextApiResponse) => {
        const UnactivatedArtists = await UnactivatedArtist.find({})
        res.status(200).json({ success: true, data: UnactivatedArtists })
    })
    .post(async (req: NextApiRequest, res: NextApiResponse) => {
        try {
            //parse form to get file Name
            const form = await parseForm(req)
            const fileName = encodeURI(form.files.file.name)
            console.log(form.fields)

            aws.config.update({
                accessKeyId: process.env.AWS_ACCESS_KEY_ID,
                secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
                region: process.env.AWS_REGION,
                signatureVersion: 'v4',
            })

            const s3 = new aws.S3()
            const post = await s3.createPresignedPost({
                Bucket: process.env.AWS_IMG_BUCKET,
                Fields: {
                    key: fileName,
                },
                Expires: 60, // seconds
                Conditions: [
                    ['content-length-range', 0, 1048576], // up to 1 MB
                ],
            })

            await dbConnect()
            const unactivatedArtist: IUnactivatedArtist = form.fields
            const locationUrl =
                'https://' +
                process.env.AWS_IMG_BUCKET +
                '.s3.' +
                process.env.AWS_REGION +
                '.amazonaws.com' +
                '/' +
                fileName
            unactivatedArtist.profile_image_url = locationUrl
            console.log({ unactivatedArtist });
            await UnactivatedArtist.create(unactivatedArtist)

            //send email to artist
            await new Email(unactivatedArtist, '45612').sendMagicLink();
            return res.status(200).json(post)
        } catch (error) {
            console.log(error)
            res.status(400).json({ success: false, message: error })
        }
    })