If you want to update the billing information associated with your Sendloop account, you can do so via the Plan & Billing page.
From the Sendloop Dashboard, click on your name in the top right corner to reveal a drop-down menu. Click Plan & Billing.
If you have already subscribed to a monthly plan or entered your credit card information before, you'll see a link to Change payment details. You'll first be asked to provide your name and address.