Preferences settings affect how Pixelmator Pro looks and behaves and they apply to all your Pixelmator Pro documents.
Press Command ⌘ + Comma , on your keyboard.
Inside, click the General, Rulers, Extension, or Pencil tabs to view and manage Pixelmator Pro settings.
Some preferences are part of your computer’s System Preferences, rather than Pixelmator Pro preferences. For example, you set the language preferences in the Language & Region section of System Preferences. To open System Preferences, click the Apple menu in the top-left corner of your screen, then choose System Preferences.