Vkontakte login doesn’t work

Hi!

Can you please help, I followed the instructions and successfully added facebook and goolge login to my website (it’s in russian, but you can see login below in comments form) – https://pokupaem-kg.ru/pitanie-pri-zhirnoj-kozhi/

However vk login doesn’t start properly. The oAuth window opens and closes immediately. Do you think it will auto fix in some time or I need to do something about it?

Thanks for your help.

P.S. I can login successfully on your demo site.

The page I need help with: [log in to see the link]