Getting "You have a new message" or don't receive notifications at all? Make sure you've enabled notifications and previews in system and in the app. Yes, it sounds absurd, but in 9 out of 10 reports people forget they've disabled the notifications.
If you're sure notifications are enabled, try one of the following:
- Disable and re-enable notifications in iOS Settings > Apps > Swiftgram
- Reboot your device
or
- Go to Debug Menu (10 quick taps on Settings/Avatar icon) and use Reset Notifications
- Reboot your device