I appreciate you for getting back to this thread, @DO_NSC.

The phone and chat support in QuickBooks Desktop are open during support hours. Beyond those suggested hours, the Community page is here to assist you 24/7. 

That being said, I recommend contacting them again to further help with your bill and purchase order concern. For detailed steps, you can follow the steps provided by my colleague above. 

In addition to that, let me share this page to help you understand Accounts Payable workflows that help track the money you owe your vendors: A/P workflow in QuickBooks Desktop.

Keep in touch if you have other questions about contacting support in QuickBooks. The Community always has your back. Stay safe!