You can delete a user to manage your account using the below steps: -
1. Open Moon Invoice application in your Web browser from this link
2. Click on Teams option from the main menu
3. You can check the user's list, Click on the Edit beside the user which you wish to remove.
4. Click on Delete User from the bottom-left corner of the Edit Access window.
5. Click on Delete in Delete User confirmation box
Once you delete the user, they will no longer have access to your account.