java kotlin expert

The app has a pomodoro timer in it as well as tasks. Within the app there is a settings screen made, I need this page to have notification settings for the app which talk with the NotificationsApp file. The user needs to be able to turn off notifications and turn them On. When turned on it needs to notify them of when the timer is complete for the pomodoro and also when their break has started and finished. The timer GUI can also be changed to look nicer aesthetically and change timer gui as per attached image.

here's code
https://www.dropbox.com/s/u7vejmkpz6ngfcb/ADHDTaskManagerApp.zip?dl=0