Hi chantal-redalelt,
Welcome to Community! QuickBooks Online offers multiple reports for all areas of your books. You can review unbilled time and expenses that haven't been added to an invoice, by following these steps;
1. From the left menu, open Projects
2. Click the customer's name, then open the Project Reports tab
3. Select View to open the Unbilled time and expenses report
You can also create a total hours worked by employee report.
If you have any other questions, feel free to reach out. We would be glad to help!