If you did participate in the beta and upgraded your Mac to the officially released version, you will still get betas of macOS updates in the App Store. Maybe you’re happy with the official golden master version, and you no longer want to get the betas. If this is the case, you need to unenroll your device from the Beta Software Program.
How to stop receiving the macOS Sierra public betas
In System Preferences, click on the App Store icon.
In the middle of the window, you’ll see a setting that says, “Your computer is set to receive beta software updates.” Click the Change button.
A window will appear asking if you want to “Stop showing beta software updates in the App Store?” If you want to stop, click on Do Not Show Beta Software Updates.
How to leave the Apple Beta Software Program
Even if you turn off beta software updates on your computer, you are still enrolled in the Apple Beta Software Program. Here’s how to leave the program.