500 (内部服务器错误)当使用Axios发送文件时

const axios = require('axios');
const formData = new FormData();
formData.append('file', fileInput.files[0]);

axios.post('/upload', formData, {
headers: {
'Content-Type': 'multipart/form-data'
}
})
.then(response => {
console.log(response.data);
})
.catch(error => {
console.error('Error:', error);
});

const express = require('express');
const multer = require('multer');
const upload = multer({ dest: 'uploads/' });

const app = express();

app.post('/upload', upload.single('file'), (req, res) => {
if (!req.file) {
return res.status(400).send('No file uploaded.');
}
res.send('File uploaded successfully.');
});

app.listen(3000, () => {
console.log('Server is running on port 3000');
});