In Settings-->Billing, scroll down, and go to Manage Payment Method:
Note: depending on which payment plan you signed up for, e.g. PayPal or Link via Stripe, it will show your default payment method on the left side there.
After clicking "Manage Payment Method", you will be taken to this page:
From there, you can add a payment method if you wish to use a new card, and make that your default payment:
There are different options you can select: Card, Google Pay, Cash App Pay, or Amazon Pay.
From there, add your card info, select "Use as default payment method" if you wish to have t hat card be charged, then click "Add".
You will now see this as the default card on file.
Please note: if you have an active subscription, you cannot remove the card on file. Once your subscription is cancelled, you will be remove the card from our system.