How does one log on to WeChat on this website?

Generally, when you log on by scanning the QR code, the page jumps to the logon page. the QR code is displayed and the QR code is scanned to log on. However, when I see this website www.lativ.com and click log on, the page does not jump to the other side, but is displayed on its own page...

Generally, when you log on by scanning the QR code, the page jumps to the logon page. the QR code is displayed and the QR code is scanned to log on.
But I saw this website, http://www.lativ.com click login, the page does not jump to there, but in their own page shows the QR code, scan the code can also log on.
How can this effect be achieved?

Reply content:

Generally, when you log on by scanning the QR code, the page jumps to the logon page. the QR code is displayed and the QR code is scanned to log on.
But I saw this website, http://www.lativ.com click login, the page does not jump to there, but in their own page shows the QR code, scan the code can also log on.
How can this effect be achieved?

Https://open.weixin.qq.com/cgi-bin/showdocument? Action = dir_list & t = resource/res_list & verify = 1 & id = open1419425505 & token = & lang = zh_CN

It is assumed that when you click the login button, he will request the API and then get the QR code through the URL to display it.

This is the second official solution:
Main purpose of JS logon: The website allows users to log on to the website without having to jump to the domain to log on and return. this improves the smoothness and success rate of logon.
For more information, see the official documentation.

Create a website application on the open platform. follow the instructions above to implement the application step by step.