如何使用post参数重定向到外部url？

<!-- 前端页面 -->
<form id="redirectForm" method="POST" action="https://www.example.com/redirect">
  <input type="hidden" name="param1" value="value1">
  <input type="hidden" name="param2" value="value2">
  <button type="submit">提交</button>
</form>

<script>
  document.getElementById("redirectForm").submit();
</script>

# 后端处理请求的代码（使用Python Flask框架示例）
from flask import Flask, request, redirect

app = Flask(__name__)

@app.route('/redirect', methods=['POST'])
def redirect_to_external_url():
    param1 = request.form.get('param1')
    param2 = request.form.get('param2')
    
    # 拼接重定向的URL
    redirect_url = f"https://www.example.com/external?param1={param1}&param2={param2}"
    
    return redirect(redirect_url)

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