See the following Apple articles:
If your payment method is declined in the App Store or iTunes Store
If your payment method is declined in the App Store or iTunes Store - Apple Support
If you see a message that says “Your account has been disabled in the App Store and iTunes”
If a message says "Your account has been disabled in the App Store and iTunes" – Apple Support (UK)
OR -> Sign in to your Apple ID account page and edit your Apple ID details.
https://appleid.apple.com
On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.
See also the following Apple articles:
Change, add or remove Apple ID payment methods
Change, add or remove Apple ID payment methods – Apple Support (UK)
Add money to your Apple ID balance
Add money to your Apple ID balance – Apple Support (UK)
Payment methods you can use with your Apple ID
Payment methods you can use with your Apple ID – Apple Support (UK)