How to develop the back-end based on the front-end source code of applet?

The specific operation steps are as follows:

1. First, open Baidu browser, and click Select to enter the "WeChat public platform" button.

2. Then click the "applet" button in the new interface.

3. click and select the "view details" button in the new interface.

4. Then enter the account number and password in the new interface and click the "Login" button.