Sharing Buttons

Hi, I have installed your theme today on my website (the site is currently in under construction mode, because it has a lot of visitors and I can’t make it public while I’m doing work on it) and everything is great, except there are not sharing buttons under the thumbnails of recent posts (home page), like there are in your demo. Do I have to enable them somewhere?

Thank you for your help and thank you for a great theme!
Katarina