The notch-totting Nokia X6debuted last month official and is currently only available in China. It has now started receiving a new update with build number of 229D.B01 that lets you hide the notch.
Other changes include portrait mode, background app restrictions, and application hide feature. There are some WLAN and game screen touch control-related optimizations as well.
The update also brings left swipe to delete for SMS and UI-related improvements. As the roll out has just begun, it may take time for the update notification to pop up on your unit, so be patient.