Hy! Checked your site and saw that you have a plugin named Share Buttons by AddToAny. Go to Plugins -> Installed plugins, click on edit for that specific plugin. It should give you access to edit what you need.
I’m afraid I can’t help you much on that. It could be in a .php file. You should try something else: install the plugin Advanced Code Editor, activate it, go to appearance -> editor, start searching in files using the icon in the upper-left corner (the find function). You could use parts of the actual addresses from the site to help you in the search.