How to show a pop-up window for a VK subscription on a website?

Question

Programming

Guys, how does the popup display for subscribing to the VK group, the condition for those already subscribed must be written so that it is not shown to them.
Script from the site for the popup: dbmast.ru/sozdaem-vsplyvayushhee-okno-pri-zagruzke...

Answer 1

1. go to VK and register your application
2. take the code for the group
3. paste it into the content of the module window from the tutorial
4. read api vk to understand if it is possible to somehow distinguish already subscribed users from unsubscribed