If you can't make purchases or update apps, including free apps, you need to update your payment method or add a new one
- Add first the new card, then remove the old one.
or -> Sign in to your Apple ID account page and edit / update 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 -> Payment methods you can use with your Apple ID
Payment methods you can use with your Apple ID – Apple Support (UK)
You can also use your Apple ID balance as payment method: Add money to your Apple ID balance
Add money to your Apple ID balance – Apple Support (UK)
What you can buy with your Apple Gift Card or Apple ID balance
What you can buy with your Apple Gift Card or Apple Account balance – Apple Support (UK)
How to redeem your Apple Gift Card or App Store & iTunes gift card
How to redeem your Apple Gift Card or App Store & iTunes Gift Card – Apple Support (UK)
If you update your payment method: It would take about 1 to 3 business days in order to process.