1. Put an Excel file on OneDrive with a Table named Reminders: Name, Email, Item, DueDate (as text yyyy-mm-dd), Status.
2. Create > Scheduled cloud flow: every day 9:00.
3. Excel Online 'List rows present in a table' (Reminders). Filter query: Status eq 'Open'.
4. Apply to each row > Condition: DueDate is less than or equal to addDays(utcNow(),3,'yyyy-MM-dd').
5. If yes: Send an email (V2): To = Email, Subject = 'Reminder: ' + Item + ' due ' + DueDate.
6. Update a row: Status = Reminded.