Apple ID breached
How do I dispute a charge made today for a game purchase that I didn’t make ?
iPhone XR, iOS 13
If this is an email you received, has your credit card been charged? Are you sure the message is legitimate? Does it contain a link for you to sign in somewhere? It may be a scam. Check your purchases history.
If necessary, contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.
iTunes Store - Contact Us - Official Apple Support.