Settings-screen rest and screen locking/screen locking-automatic screen locking. You can choose the automatic screen locking time of 15 seconds, 3 seconds, etc. You can choose the specific screen locking time according to your needs.
Tips: At present, there is no "Never" option for all models with OLED screens to automatically lock the screen. If there is a need to keep the screen on for a long time, it is recommended to choose 1 minutes.