How can I update a customer's credit card information in Bold Subscriptions for Shopify?
Bold Subscriptions does not store credit card information. All payment information is stored in and managed by Shopify. Subscribers can manage their payment method tied to their subscription by clicking "Change Payment Information" in the customer portal.
This will send the email from Shopify to update their credit card information. If there are any problems receiving this email or updating the information, please reach out to Shopify for more help.
Alternatively, you can also update a customer's payment method on the customer edit page in your Shopify admin. More details can be found in Shopify's article here - https://help.shopify.com/en/manual/customers/manage-customers#edit-a-customers-subscription-payment-information.