Thanks for replying into this thread, @Davidbowers.

I appreciate you for following the instructions that my colleagues have shared. Allow me to provide you with another workaround to address this. 

Invoices can also be downloaded in PDF format, and will be kept on your computer and send through your Gmail account directly. Follow these steps to download an invoice:

1. Go to the Sales menu.
2. Select Invoices.
3. Find and select the invoice you want to download.
4. From the Action column, click the dropdown and select View/Edit.
6. Click on Print or Preview, then select Print or Preview again.
7. Select Download.
8. Select Close to exit the PDF viewer.

Once downloaded, you can now send the invoices using your Gmail account. I'll also provide this article for more details on downloading sales forms in QBO: Download and save sales forms and statements in QuickBooks Online.

You can also visit this article to learn more about sending multiple invoices: Email or print multiple sales forms in QuickBooks Online.

Let me know if you have any additional questions concerning invoices. I'm always around to help. Keep safe.