how to send and receive file by flask and axios

Question

In the node js, I send a post request, and hope to receive a file from the python flask server. What it sends is not relavent, and I just would like to receive the a jpeg file from the flask server:

const fs = require('fs');

const axios = require('axios');

const BASE_URL = "http://localhost:5000";

function send_test(test_name,...args) {
    const apiurl = `${BASE_URL}/send`;
    
    
    const form = new URLSearchParams();
    form.append('filename', test_name);
    const config = {
        headers: {
            'content-type': 'multipart/form-data'
        }
    };
    axios.request({
        url: apiurl,
        method: 'POST',
        headers:config,
        data: form,
    
    })
        .then(function (response) {
        
            
            console.log(response.data);
            fs.writeFileSync('result.jpeg', 
            response.data);
        
  })
  .catch(function (error) {
        console.log(error);
        
  });

}
result = send_test('test_name');

The flask server returns a jpeg, and it does not matter what it receives from the node js, it does not check the form and just sends a jpeg file:

from flask import Flask, request,send_file
import os

app = Flask(__name__)


@app.route('/send', methods=['POST'])
def send():
    print('send')

    extracted_name = 'test.jpeg'
   
        
    return send_file(extracted_name, mimetype="image/jpeg")

However, when I save file to 'result.jpeg', the file cannot be opened. I think the encoding of the file is important here. How to save the file by fs.writeFileSync()? The first a few bytes of response.data is like :

����JFIFHH��xExifII*1>i�FPicasa�0220�� ���C