Please check:
You need to have a good Service & Wi-Fi.
If they are On, turn Off Hotspot & VPN.
Charge the battery > 70%.
See also -> If you can't connect to the App Store, iTunes Store, or other Apple services
If you can't connect to the App Store, iTunes Store, or other Apple services - Apple Support
-> If you tried all of the above steps and you still can’t connect, contact Apple Support.
Then try to update your card information:
You need to -> Sign in to your Apple ID account page and edit / update your Apple ID details.
On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.
Or -> Add a payment method to your Apple ID
Add a payment method to your Apple ID – Apple Support (UK)
- If you want to change your card, you need to add first the new card, then remove the old card.
- or if you use your Apple ID balance, you need to set your Apple ID balance as your default payment.
If you update your payment method or add funds to your Apple ID balance, It would take about 1 to 3 business days in order to process.
If you're still unable to update your payment method, Contact Apple Support.
Click here for more support and assistance.