Apps are allowed to display notifications on the Samsung device by default. The notifications can be turned off for an app either completely or in individual areas. For example, for WhatsApp, notifications for group messages can be turned off via the app settings. Each app offers its own setting options for this purpose, but they can all be found under Notifications.

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Apps
Step 3:  Tap on desired  App
Step 4:  Tap on  Notifications
Step 5:  Enable or disable  Show notifications
  1. Open the Settings
  2. Tap on Apps
  3. Tap on desired App
  4. Tap on Notifications
  5. Enable or disable Show notifications

Samsung Instructions