Can't be done on that card. It has only ONE output. You need three outputs of some kind in order to game on three panels. You need a different card. You can get display function through other methods, such as USB or iGPU in some cases, but you will not be able to use those outputs for gaming with a three panel configuration, or even two panel, on that card.
Besides which, you'd be stuck with low settings, if at all, even if it HAD the outputs, because you'd be trying to drive triple the number of pixels and that card would not be capable of doing it on any decent settings, on any AAA games. Maybe on some light demand eSports games, but since it lacks the outputs, it's a moot point anyhow.