I can’t download apps on my iPhone
Why I can’t download any apps and it requesting for credit card
Do you have a payment method attached to your Apple Account? Even free apps require a payment method since most offer paid upgrades and in app purchases. Instructions to add a payment method are below.
Add a payment method to your Apple Account - Apple Support
If you do have a payment method on your account, then please contact Support for assistance.
To contact Support, do this:
1. Click on this link --> Choose your country or region - Official Apple Support
2. Select your country
3. Select: Billing & Subscriptions
4. Select: Subscriptions & Purchases
5. Select: Update payment method
6. Select a chat session or a phone call.
Copied from iTunes support - Apple Community