Let's figure out what's preventing you from seeing those invoices in your Gmail account.
Are you referring to your customer invoices? Let's make sure to turn on the CC or the Email me a copy option on the Account and Settings page. If this is turned off, you won't be receiving any invoice copies when sending them out.
To turn the option on:
Go to the Gear icon, then select Account and settings.
Click the Sales tab.
Expand the Messages section.
Check Email me a copy at option or enter your Gmail address on the Copy (Cc) new invoices to address box.
Hit Save, then Done.
However, are you referring to your emailed subscription invoices for QuickBooks Online? The primary admin normally receives the subscription invoices. Make sure you're checking the email address associated with the primary admin account.
Check the junk or spam folders if needed (the same goes for emailed customer invoices). This is also likely the reason why you're not seeing those emailed invoices.
Alternatively, if you want to check your monthly billing statements, we can go to the Billing & subscription page:
Click the Gear icon again, then select Account and settings.
Go to the Billing & subscription tab.
Review the payment history section for the statements.
If you don't see the invoice history, or if you're not receiving it in your Gmail account, let's contact the support agents. They can give you the subscription invoices, and help you fix the delivery issue.
After managing your emailed invoices, do you need to compare your Profit & Loss report with a different period? Check out this article as a guide: Run a Profit and Loss Comparison Report.
Feel free to reply here if you have more questions about the invoices. Did you encounter any difficulties while managing other entries or reports? Let me know and I'll get back to you as soon as possible.