Header edit

Hi, is there any way to set some image as meta property in header for whole site? <meta property="og:image" content="http://solveprague.cz/wp-content/uploads/2016/06/cropped-Solveprague_logo.png" /> I have tried some plugins to edit header, but it doesn´t look it´s actually working. I would also need to add Facebook pixel tracking code. Thanks a lot, Petr