You can modify the Kiosk setting to allow or disallow system and app notifications. You may set up your device to display the information you allow only.
Please refer to the following steps to adjust the notification settings:
1. Go to Admin Console > Policy & Kiosk > Policy & Kiosk Config Files > select an existing Kiosk-related Config File > Edit
2. Choose Kiosk Launcher > Notification Center > Toggle on the Notification Center and Allow USB Notification (Beta)
After these steps, the devices under the Kiosk are allowed to receive and display the notification.