The Niō app includes a video resolution toggle, which lets you toggle between 1080p HD and 4K video. This toggle is located in your Niō's settings, under ‘Camera’. Using this toggle will change the resolution of all new recordings.
The resolution of the camera's live view will be 720p, regardless of which video setting you choose. However, with the 4K setting, the live feed may appear to look higher quality - due to the higher bitrate required for 4K.