Follow @Brucanna’s instructions, which were quite complete. But perhaps you were confused because the control account and cash account were given the same name in the example.
You create a custom control account as a liability account. You create a credit card account as a cash account because that is the only type account from which you can spend, receive, or transfer money. When you create the credit card cash account, assign it to the custom control account you just created as a liability account. Otherwise, it will default to the
Cash & cash equivalents asset account.
If you want to keep things simpler, you can leave out the custom control account, but then, your credit card transactions will show up as a contra asset account rather than as a liability.