Solved with a free version of “Admin Columns” plugin and custom fields.
Nevermind, I forgot to install Jetpack plugin. This one’s on me.
Also, I’m not able to create social links menu, there is no such option both in Customizer and back-end admin panel.
It’s a self-hosted WordPress site, you can find it here:
http://brightdesign.pl/pik
Problem solved, I re-uploaded WordPress files and it started working.
