"Contact www.apple.com.support.iTunes" pops up when trying to purchase on App Store

Re: When I try to buy stuff like robux it keeps saying it’s an error

Apple Support have articles online (links below) that may be helpful:

What to do: If you can’t download or update apps on your iPhone or iPad - Apple Support

or

If your payment method is declined in the App Store or iTunes Store - Apple Support

Also:

There are "Get Support - start now" links (online chat / phone / email etc.) at the bottom of each website below:

You could try reaching out to App Store Support ... App Store - Official Apple Support

or

Find answers to your questions about purchases, subscriptions, payments, and billing:

Billing and Subscriptions Support website: Subscriptions and Billing - Official Apple Support

or

iTunes Support Website: iTunes - Official Apple Support

or

See a list of Apple phone numbers around the world

Contact Apple for support and service - Apple Support