How do I update invalid credit card on my Apple Account?

Re: I am not able to change to a different credit card to pay for my storage

As your account has an active subscription:

you would need to add a new payment method before you could remove the old one.

See which payment methods Apple can accept in your country or region:

Payment methods that you can use with your Apple Account - Apple Support

See what to do: If you need to change or update your Apple Account payment method - Apple Support

or

how to: Add a payment method to your Apple Account - Apple Support

and

How to: Remove a payment method from your Apple Account - Apple Support