You need to enable push notifications for the Barion app to access Barion features.

Here's how to do this:

1. Go to the "Settings" app on your device.
2. Tap "Notifications" on iPhone, or Notifications > App settings on Android.
3. Scroll down on iPhone, or tap "All apps" on Android to see the list of installed apps, and select Barion in the list.
4. Select "Allow notifications".