stripe-react-serverless-34.ts

class StripeManager {
  ...

  public static async updatePaymentMethod(customerID: string, paymentMethodID: string) {
    await fetch('https://your-endpoint/stripe/update-payment-method', {
      method: 'POST',
      body: JSON.stringify({
        customerID,
        paymentMethodID,
      }),
    });

    // Update your user in DB to store the new payment method
    // updateUserInDB() is *your* implementation of updating a user in the DB
    updateUserInDB({ paymentMethodID });
  }

  ...
}