From the Invoices page in your Optix dashboard, you can access all invoices created, and have the ability to filter these invoices by a particular user. You can do so by typing their name in the search box at the top right of the page.
Another way to do this would be to:
Click Users
Select the user in question
From the right panel that appears, select Invoices
From this screen, you can see all invoices associated with this account. Clear the preset filters by hovering over the ‘status’ bar and clicking the x
Lastly, you can also access a user's invoice by navigating to the Invoice items page under Invoices in the right panel.
Need more info on Invoices?