How to make authorization on the site through VK Connect?

Question

JavaScript

On https://webium.ru/ , authorization through VK Connect is very cool and beautifully done. How can I do the same, where to read the documentation?
I read it here - https://dev.vk.com/api/open-api/getting-started , but there authorization is simple through VK

Answer 1

For this, HTML CSS JS and PHP are used. All registration is arranged using PHP.