vkontakte-api – Get user id VK

Question:

Tell me a way to quickly get the id of a VK user who visited my site.

I have a button, and by clicking on it, the VK window should appear, and after permission, I should get the id or immediately the name and url to the avatar picture.

Everything should be without reloading the page.

Answer:

<script src="//vk.com/js/api/openapi.js" type="text/javascript"></script>
<script type="text/javascript">
VK.init({
    apiId: код приложения
});
function authInfo(response) {
  if (response.session) {
      console.log(response.session.mid);
  }
}
VK.Auth.getLoginStatus(authInfo);
VK.Auth.login(authInfo);
</script>

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