Here are the steps to take to update:
Log into your account
Visit your [My Agency] tab
Click the [Billing] sub-tab to update information. See screenshot here --> https://simon.d.pr/ULF74g
If you do not see the [Billing] sub-tab, then you may not be listed as an account administrator. Ask that person to log in, or reach out to our customer support team at 1-888-764-0633