iPhone 13 locked by 'Find My iPhone' after update

Unfortunately the seller not providing you the Apple Account credentials that the iPhone is locked to was likely intentional. This is a common scam and in most cases the iPhone locked was either lost or stolen and is being sold by the thief.

You won’t be able to unlock it as you are not the original owner. Please drop it off at your nearest Apple Store or local electronics store to recycle it responsibly.

Please read this User Tip and next time reconsider whether you want to purchase used Apple products:

The All Too Common SAD Reality of Buying … - Apple Community

As I already explained......Apple will not help unless the sales receipt clearly shows that you were the original owner of the phone along with the date of the sale and serial number of the iPhone.

Since you purchased the phone from another person, you cannot be the original owner.

But, you don't have to take our word on this. You can contact Apple Support to confirm.

Support

Apple will confirm that you need to contact the person that sold the phone to you and have them remove the phone from Find My and the list of devices using his Apple ID and Apple ID Password.

Good luck. If the person that you bought the phone from will not return your calls or messages.....there is probably a reason for this.

I am sorry, but until the seller provides his Apple ID and Apple ID Password to you, or the seller removes the phone from Find My, you will not be able to unlock the phone.

Apple will not be able to help you with this unless you are the original owner of the phone.

Unfortunately, since you purchased the phone from another person, you would not be able to meet the Apple requirements for unlocking the phone.

The receipt needs to be from Apple and have your name on it. The box doesn't matter.

The All Too Common SAD Reality of Buying a used iPhone- Apple Community