How can I stop an employee who uses quickbooks from accessing reports
To do this, you're going to need to change the users access rights. Here's an article on adding, deleting or changing user access that can help determine what restrictions are available. I'm going to list some steps for you to follow to accomplish this as well.
Select the Gear ⚙, then Manage Users.
Find the user you want to remove access from, and select Edit in the Action column.
In the window that appears, choose the Standard User
You will now how a couple options for customizing access. As you select them it will display what the user can and can't see with the options selected.
Once you are done, press Done in the bottom right corner.
Let me know how it goes, and if you have any other questions feel free to reach out to me again.