1.notify_url

:http:///payCenter/payFinish
:http://ip:port/payCenter/payFinish

2. Local private network traversal is used. The notification address is as above
everything is normal. After successful payment, you can receive the callback notification from Wechat

3. After the application runs on the server and the notification address is paid with the first
above, the callback notification cannot be received, and the following verification has been done:

Open the browser and directly use url to access that address. You can access
Alipay and UnionPay pay. The local test code above
is exactly the same. The only difference is the callback notification address. But I can access that address directly with the browser url

I hope that the boss who has the experience of scanning code payment will help me solve my doubts. Thank you very much.