In the top right corner of the screen click on the tool icon and choose the Property Settings / Financial Settings / Currencies & Accounts:

In the bottom of the window, you will see the list of Accounts and Payment Methods.

To add a new account, click on the Add Account button on the right.

You will see the Edit Account window:

1) Account Name: Place the name of the account.

2) Access: Choose which staff role will be able to view the transactions of this account.
Read here: Setting up Roles & Permissions

3) Invoice series using: Choose the invoice series that should be chosen for transactions made for this account (more information about invoice numbers and series)

4) Determine if the account is active or not *

5) Check this option in case you want this account to be counted during shift switch.*

Next, save and close the new account. 

You can assign an account to the selected booking method (Credit Card):

An account selected as Credit Card will appear under Credit Card button in Take Payment view. All other account will be available under Accept Cash button.