I can’t update or download app it’s keep saying verification required billing information

You see the ‘Verification Required’ popup because of an error with the payment method currently connected with your Apple ID. You get this message when a payment method has failed, or if the particular device has never purchased a paid app, or downloaded a free app, or if there is a pending unpaid balance on the account.

The leading cause for the ‘Verification Required’ message on your iPhone is a faulty credit card. To get rid of the issue, you have to change your Apple ID payment method.

Ref: Payment methods you can use with your Apple ID - Apple Support