Well, the problem is that social login is working fine on standard themes, but not on my theme. What's the problem?
On my theme it is showing:
[OneAll Social Login] To enforce the security of our services we require each domain to be whitelisted. Please click here to open your security settings and whitelist the domain worldpress.com.ua. Reload this page afterwards.
Here is a link to the website: http://worldpress.com.ua/podpiska
And same in the comments.