You cannot use your credit card for paying another credit card bill. You can, however, consolidate debt. You can do this by transferring your existing balance to a different credit card. With a balance transfer, you can effectively limit interest charges, but you will likely need to pay transfer fees.
You may also use the prepaid cash advance of a credit card for paying off debts you owe on a different card. However, you will get charged a higher APR (typically around 25% or higher). If you opt to use these methods, it may help you in consolidating your card debt at a critical juncture. But if possible, it’s always better to pay the full amount.