如何将JavaScript变量发送回flask？

var data = {
  variable1: 'value1',
  variable2: 'value2'
};

// 使用AJAX发送POST请求到Flask应用的路由
var xhr = new XMLHttpRequest();
xhr.open('POST', '/route', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    // 请求成功后的处理代码
    console.log(xhr.responseText);
  }
};
xhr.send(JSON.stringify(data));

from flask import Flask, request

app = Flask(__name__)

@app.route('/route', methods=['POST'])
def route():
    # 获取POST请求中的数据
    data = request.get_json()
    
    # 处理数据并返回响应
    result = process_data(data)
    
    return result

def process_data(data):
    # 处理数据的业务逻辑
    return 'Data processed successfully'

if __name__ == '__main__':
    app.run()