Problem on saving Multiple Files in Multer - node.js

Question

I am Selecting Multiple Files and using Multer saving Files to a specific folder. But if i am uploading Single file it is working Fine but if Selected More than two it is giving me an
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client. I am frustrated solving it. Can anyone one help me out yrr.
<div className="mb-3" >
<CFormLabel htmlFor="formFileMultiple">Select Resources</CFormLabel>
<CFormInput
multiple
onChange={(event) => formikProps.setFieldValue('fileName', event.target.files)}
accept="application/pdf, application/zip"
type="file" id="formFileMultiple" />
<p style={{ color: 'red' }}>{formikProps.touched.fileName && formikProps.errors.fileName}</p>
</div>
const handleAddResources = async ({ fileName }) => {
try {
const data = new FormData();
// data.append("fileName", fileName);
data.append("courseId", props.currentUser.item.course_id);
for (let i = 0; i < fileName.length; i++) {
// newArr.push(fileName[i]);
data.append("fileName", fileName[i]);
let response = await axios.post(`${ConfigData.SERVER_URL}/admin/resources/addResources`, data, {
})
if (response.data.status == false) {
throw Error(response.data.message)
}
else {
console.log("Success")
setthrowAlert(true);
}
}
} catch (error) { console.log(error) }
}
router.post('/addResources', fileUpload.array('fileName', 100), async (req, res) => {
try {
if (req.body && req.files) {
req.files.map(async(item) => {
console.log("ITEM--->", item);
let ResourcePost = new ResourcesPost({
originalname: item.originalname,
FileName:item.filename,
courseId: req.body.courseId,
mimetype:item.mimetype,
encoding:item.encoding,
size:item.size,
destination:item.destination
})
let uploadData = await ResourcePost.save()
if (uploadData) {
res.status(200).json({ status: true, data: uploadData })
} else {
res.status(500).json({ status: false, message: err.message })
}
})
} else {
console.log("Resourses Not Found !");
}
}
catch (error) {
console.log(error);
}
})