How do I cancel a recurring charge on an Apple Card?

A recurring charge from where?

If it appears as "apple.com/bill", then check your Apple ID subscriptions and cancel any you don't need by following the steps in the support document linked below.

click here ➜ If you want to cancel a subscription from Apple - Apple Support

If you subscribed directly through the provider's website using Apple Pay, then you will need to cancel said subscription directly through the provider's website.

Cancel your recurring charge by canceling the charge with the merchant. Trying to block a merchant or a charge is not the way to cancel a recurring charge.