Charges

This is primarily a user-to-user support forum; other Apple users like you.

If you have checked subscriptions as described in How to cancel a subscription from Apple - Apple Support and it doesn't show there, another possibility is that it is a charge for iCloud storage upgraded from the free 5GB to the 5)GB plan. See the following for how to check your plan and to downgrade: Downgrade or cancel your iCloud storage plan - Apple Support

If neither of the above helps, see each of the steps in the following instructions. They include information on contacting Apple Support if the other steps don't help: If you see 'apple.com/bill' or an unfamiliar charge on your statement - Apple Support

It's your extra iCloud storage.

Cancelling the extra storage will revert you to the 5GB free plan and will remove anything over that.