Unauthorized subscription charge on Apple Account

Review your Purchase History here:

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

And view/manage subscriptions here:

View or cancel app subscriptions on iPhone - Apple Support

Subscriptions renew automatically and a free trial will become a subscription if you do not cancel the trial a day before it ends. Let us know what you find out or post a screenshot of what you see at those links.

A charge managed by Apple on your device only happens when you authorize the charge by double clicking the side button with the charge details on the screen followed by verification with Face ID/Touch ID or Passcode. For a free trial, the authorization screen shows:

• Free trial period
• Subscription Start Date
• Subscription Price
• Subscription Length
• Message stating to cancel at least a day before the Subscription Start Date to avoid any charges.

Here are the four usual causes, and what to do about each: Billed, but you didn’t buy? - Apple Community