Nothing happens when an alarm rings and I press the snooze button

If you have the following icon displayed on Kello:

It means that the Snooze feature is turned off. Check the following items:

➡️ Make sure you haven't turned off the Snooze in Kello's settings:

➡️ Make sure you don't have any Snooze Less program running. If you have one, it means that you're out of Snoozes for the week! Simply stop the program to be able to snooze again.

➡️ Make sure you're not trying to snooze an Important Alarm. By default, Important Alarms can't be snoozed.