How to change og:images

When you put a link to your gkevents site on whatsapp, this app returns an image of the site but in my case returns a logo of Gavick. Reading on internet I saw this image is called og:image
Where in the template or code I could change this image with my own logo in gk_events?
Thank you.

Hi

I would advice to use some 3rd party plugin. You can find a couple here: http://extensions.joomla.org/extensions ... aph&filter[tags][]=&filter[core_catid]=&filter[includes]=&filter[versions]=&filter[type]=&filter[hasdemo]=&filter[newupdated]=&filter[score]=&dir=DESC&limitstart=&controller=filter&view=extension&layout=list&Itemid=145&clearorders=0&clearfilters=1