1. Check that your phone is set to Ring or Vibrate mode
2. Check the volume setting on your device
3. Try restarting your device
4. Check for updates by going to Settings > General > Software Update
5. Check that your alarm sound is not set to None
6. Check if the Do Not Disturb option is turned ON
7. Check your alarm time settings are correct
8. Make sure to select Repeat for an alarm to happen every day