MacBook Air Shut down prompt

Hi Suzzukii,

Thank you for posting in Apple Support Communities! Do you notice if this is happening with using a specific app or performing a specific task? Are you getting a pop up asking you to shut down, restart or put your device in sleep mode?

If you go to the Apple menu (  ) > System Preferences > Battery > Schedule, do you see any specific schedule time for Mac to start up, shut down, etc?

Check out: Schedule your Mac desktop computer to turn on or off - Apple Support

Are there any updates available for your Mac? You can confirm by going to the Apple menu (  ) > System Preferences > Software Updates.

Update macOS on Mac - Apple Support

Hope that helps!