Most likely your integrated graphics chip doesn't support a 27" screen and can't manage anything beyond 1920 x 1080.
How you connect it to your PC has no bearing on what resolutions are available, it's all down to how much video memory is available, and since integrated graphics chips have to share system memory, there just isn't enough.
You either need a decent graphics card (minimum 2GB VRAM) or a smaller monitor.
Whilst Windows can stretch the graphics output from your existing integrated GPU to fill a 27" screen, it will have an adverse effect on clarity & sharpness compared to using the monitor's native resolution.