Auto Email to Suppliers for Purchase order due date 2 days ego

Hello Team
Please Help me setup an Auto Email to Suppliers against the Purchase order for the Reminders Due date of Delivery Material, for example, 2 days ago.

That for, you should use the Notification.

doc.due_date==nowdate() in this what I write if I have to send this 2 days ago of required date.

Please check it.