Is your credit card expired or do you need to change the card details that are connected to your account, there is no need to worry. You can update the card details by click your profile icon within the right hand corner. There will be a dropdown and you will need to select "Payments".

From there you will be directed to page that looks as below. Here will find your previous card details, however if you have no card connected you will need to add a new card. 

Once you select "Add New Card" you will need to add in your card details and then click submit. Once submitted, your card will be charged with the cost of each deal once it's approved, and the remaining cost per click (maximum reached will be your budget) of the deals will be charged post the event.