Can I filter by not sent?

Thanks for posting in the Community!

You can run the Transaction List by Customer report to view invoices to be sent in your QuickBooks Online account. Here's how to run the report:

1. Click on the Reports tab.
2. Search Transaction List by Customer.
3. Click on Customise.
4. Click on Filter, and under Sent field, select To be sent.
5. Click on Run report.

Furthermore, you can also go to your Sales tab section and under Status column you'll see the invoices status from here.

You can check this link on how to customise report in QBO: Customise reports in QuickBooks Online.

Post again in the Community if you have further concerns about running report in QBO. I am around to assist you.