I am not able to download any app

You need to --> Change, add, or remove Apple ID payment methods - Apple ...

If you can't choose None when you edit your Apple ID payment information

1. If you have an unpaid balance or payment due
2. If you have a subscription that automatically renews
3. If you're using the iTunes Store or App Store for the first time
4. If you are not in the country or region you’re creating an Apple ID for
5. If you changed your country or region
6. If you're a part of Family Sharing

Something must be updated in your payment method. See this article:--> If your payment method is declined in the App Store or iTunes Store - Apple Support

Regards

Giulio