What is this 99.99 dollar charge on my apple accout

If you're sure that the charge comes from Apple (check your bank statement very carefully, ignoring scam messages that might be addressed to your iPhone), start reading this support page:--> Subscriptions and Billing – Official Apple Support, and check each of the first 3-4 sections.

If you cannot find the information you were looking for, please contact iTunes Store Support Team directly and explain your problem, using this specific link:--> Apple Support

(if you get no help, look at the bottom of the link, where you can contact them using "chat" or "phone" options).

Regards

Giulio

See the following Apple articles:

View your purchase history for the App Store, iTunes Store, and other Apple media services

View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support

How apps, content, and subscriptions from Apple are billed

How apps, content, and subscriptions from Apple are billed - Apple Support

If you see "apple.com/bill" on your billing statement

If you see "apple.com/bill" on your billing statement – Apple Support (UK)

If you still need help, get more help and assistant from Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK)