If you haven't seen that screen, follow these steps to check if the device is ready to use: Don't take ownership of any used iPhone, iPad or iPod touch if it's protected by Activation Lock. On a device with iOS or iPadOS 15 or later that is protected by Activation Lock, you'll see an 'iPhone Locked to Owner' screen when you turn on or wake the device.
Before you buy an iPhone, iPad or iPod touch from someone other than Apple or an Apple Authorised Reseller, make sure the device has been erased and is no longer linked to the previous owner's account.