If you want to be notified of scheduled and deadlined tasks in Org mode, there is no better way than with org-yaap. It has zero dependencies other than Emacs 27.1 and it works great on Android with termux.
I've been using it for two years without issue. The documentation and options are superbly setup to fit most uses of Org:
"""
By default, you will be notified for all scheduled headings (org-yaap-include-scheduled') and headings with a deadline (org-yaap-include-deadline') within your agenda files. If a heading only includes the date, you will be notified at 9am on the day of the heading (org-yaap-daily-alert'). If you don't mark a heading as done, you will be repeatedly notified every 30 minutes after the heading was due (org-yaap-overdue-alerts').
"""
