Is there a function to send out FINAL NOTICE to customers?

Hi adelaide-north,

Welcome to Quickbooks Community.

If you have invoices or outstanding balances of customers that will soon be overdue, you can send  a customer statement. This article will guide you step by step on how to create and send a customer statement Create and send customer statements in QuickBooks ... (intuit.com)

Hope this answers your questions. Feel free to reach out again if you have any other questions.