Resolutions

Hello,
I use a 27Inch 2560x1440 144hz monitor. I used to play crossfire alot many years ago and have returned to the game since some friends have started playing it again. The maximum supported resolution is only 1920x1080 from what I can see ingame? How can I make it render to 2560x1440?

I do not need the textures to be running that resolution. I just want the edges of objects to be sharp as at the moment they are just jaggy blurry edges since the low resolution. The textures being blurry I can cope with. How can I get a good resolution to run on the game?

Thank you!