Good morning,
I am not sure what you mean by "coroner", but regarding sending invoices using Quickbooks Online (Plus), you can definitely see the status of an invoice sent to a customer. You do that my going to "Sales" on the left sidebar and then click "All Sales". It will then bring up all of your open sales transactions and there should be a column that says "Status". That column will show you whether an invoice has been sent, viewed, etc.
You can click on that particular invoice and when that invoice opens up, you can scroll to the bottom of the invoice and it will show all of the activity with a time stamp that shows everything from the moment you sent the invoice.
I hope this help you. I apologize if I misunderstood the question.
Have a good day.