Hi there, @gisearthworks-gm . I'd be happy to help you recover the deleted invoice in QuickBooks Online (QBO).
In QBO, the option to undo the deletion of an invoice is unavailable. You'll have to recreate it. To do so, let's use the Audit log report to take note of the details of the deleted transaction. I'll guide you on how:
Once everything is fine, your next step is to record payments for your customer invoice.
Keep me posted if you have any other concerns about managing invoices in QBO. I'm just around the corner to lend a hand. Have a good one and stay safe.