How to authorize the site through a closed VK group?

Question

PHP

I'm trying to authorize the site through the Vkontakte login, but I want to make it so that only those who are in my closed Vkontakte group can enter. I rummaged through the entire Internet and did not find the necessary information .. I'm making a website on WordPress. installed the Easy VKontakte Connect plugin. Login through VK works, but the restriction through the group cannot be done.
Can you please tell me where to get information?

Answer 1

After receiving information about the user, send a request to the method - https://vk.com/dev/groups.isMember - if 1, then add data to the database and write it to cookies.
if 0, then just display a message

YOU WILL NOT PASS!!!

and all.
What is so difficult about this that you searched the entire Internet and did not find it? It took me 1 minute for everything about everything.
As I understand it, you don’t know shit about this and want such a function to be written for you, but alas .. either yourself or $$$