The following video (German) will show you how to create a cash, postal or banking account (accounts for liquid funds). A cash account is created in the example. Follow the same steps to create a banking or postal account but also add your bank's details.
The account remains in the chart of accounts. You must delete this manually if necessary.
To find out how to set up ESR for your postal or banking account, read "How can I set up orange payment slips for my account?".