Go to 'Invoice' => 'Configuration,' and in the settings, enable email notifications by setting it to 'true.' Then, click the 'Configure Reminder' button to set up due day reminders.

The due reminder list view looks like below.

Click the 'Create' button, enter a reminder name, and set the number of days for unpaid invoice reminders.

Schedule cron job information as below. Please take care to change execution. It's possible to affect to your reminders if it's not expecting every day.

The unpaid invoice email looks like below.

If you want to avoid sending customers notifications, then check 'Don't send unpaid email notification' so that customers will not receive overdue invoice emails.

You can view the reminder history from the invoice.

If you open the reminder history, it will show notifications for viewing emails.

The unpaid invoice email looks like below.

Go to 'Invoice' => 'Configuration.' In the settings, set 'Email Notification' to 'true' to enable email notifications. Then, press the 'Configure Reminder' button to set up the reminder. You can send email notifications based on the invoice date or the due date. In this case, we choose 'Due Date' to send an email notification.

The due reminder list view looks like below.

Press the 'Create' button and enter a reminder name, reminder days, and a template to set up unpaid invoice reminders. You can either create a template or select one from here.

You can see the invoice due date.

Now, go to the scheduled actions and run them manually.

The unpaid invoice email looks like below.

You can view the reminder history from the invoice.

Now, we are sending email notifications based on the invoice date. To do this, go to 'Invoice' => 'Configuration,' and in the settings, set 'Email Notification' to 'true' to enable email notifications. Press the 'Configure Reminder' button to set up the reminder. In this case, we have chosen 'Invoice Date' to send email notifications.

We are creating a reminder, so please provide a reminder name, reminder days, and a template to set up unpaid invoice reminders. You can either create a new template or select one from here. We are creating a new template here.

Form view of the email templates. Write a name of the template and content.

Form view of the invoice due reminder.

You can see the invoice date.

The unpaid invoice email looks like below.