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I have bought a new phone that was second hand and the person did not give me their Apple ID so I can not get into the phone and I have not been able to get in touch with them.
iPhone 11
Question marked as
you will need to contact the previous owner to have them log out of iCloud or go to https://www.icloud.com/find/ My Phone and erase the device, then remove it from their account. If you can’t do that, the device is useless. Apple won't unlock it.