If you are in charge of payment for yourself or your team, you can edit your payment on the app. 

First, open up your app and go to Profile in the main navigation. Then click Payment.

If you haven't selected a plan yet, you'll be prompted to make a selection.

Next, you'll be prompted to select payment type. Click Credit / Debit Card to use this payment type. Then enter your card information and click Next. Your card will be charged the amount indicated.

Note: Only business owners or team admin are able to edit payment. If you do not see the Payment option in your Profile, then your Team Admin will have to manage payment.