To enable the notifications, go in "my watch" page (press watch icon in top right corner of the screen), the in "notifications" menu. Here you can select/deselect the notifications you want to receive on your watch.
Note for iOS Users
In order to ensure the good reception of your notifications, please proceed to the following steps:
You can get notified for calls, SMS and most of the most popular messaging or social media applications.
Open your AlpinerX app and select "general" under the "settings" tab in your main menu. Then press on the button next to "notification with sound" to enable or disable sound.