To get out of the PUBG MOBILE Mobile BETA program, you can uninstall the BETA version of the app and install the regular version from your app store [1]. If you need further assistance, you can contact PUBG MOBILE Mobile support through the in-game settings or the login menu [2].
The update may not be available to everyone yet. Once it becomes available, you can install it through the Play/App Store or through the PUBG MOBILE MOBILE website (https://www.pubgmobile.com/) [1].