Sorry but our keyboards do not support this right now. If you want longer idle time, you can try the following combos:
fn+S+L+R: Set the auto sleep time to 10 mins;
fn+S+L+T: Set the auto sleep time to 20 mins;
fn+S+L+Y: Set the auto sleep time to 30 mins;
fn+S+O: disable auto sleep.
*K Pro series keyboards (K8 Pro, K6 Pro, and K2 Pro) cannot set auto sleep time but they will automatically enter sleep mode without being in use for 2 hours.