How the hell do i set my 4k display to 1440p?

I do have massive issues trying to set my display resolution to 1440p - wich seems to be the sweetspot for a lot of games like Monster hunter world, Horizon zero dawn etc. to not drop below the 60 fps mark. so PLEASE respond asap - after all i spent an insane amount of money on an laptop, wich would be easily capable of delivering the stuff have set as a low bar for games. Thanks, and have a cookie!