unknown payment

You are seeing a scam.

Did you provide any potentially damaging information to anyone? If yes, you'll need to follow up, for example, with a credit card company, Apple, your bank, etc.

If you gave you Apple ID password to a scammer, then

Change your Apple ID password https://support.apple.com/en-us/HT201355

Here is What to do [before] or after you change your Apple ID or password https://support.apple.com/en-us/HT204071

Learn about/Increase security

See If you think your Apple ID has been compromised https://support.apple.com/en-us/HT204145

Increase the Security of your Apple ID https://support.apple.com/en-us/HT201303

iCloud security overview  https://support.apple.com/en-us/HT202303

Ways to keep your information safe on Mac https://support.apple.com/en-gb/guide/mac-help/mh11402/mac

Learn about Phishing, Apple Practices,etc.

 See If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement https://support.apple.com/en-us/HT201382

See Identify legitimate emails from the App Store or iTunes Store https://support.apple.com/en-us/HT201679

See How to avoid scams when using Apple Pay to send and receive money https://support.apple.com/en-us/HT208226

For scam related information from Apple including reporting scams to Apple see Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams https://support.apple.com/en-us/HT204759

If there was an actual charge to your credit card.

Apple ID - If you see ‘itunes.com/bill‘ or an unfamiliar charge on your bank, credit card, or debit statement.

If necessary, contact iTunes Support.

iTunes Store - Contact Us - Official Apple Support.      

Is there a charge on your credit card or not? There are a lot if scams. They’re persistent, and targeted. That link is phishing for your Apple ID credentials, if this is typical. It’ll be a fake Appke login portal.