: Use icloud.com to remotely erase and reset your device if you know your Apple ID.
Are you trying to bypass a (like an iCloud Activation Lock or a forgotten passcode) so I can point you to the right official guide?
: Ensure your specific iOS version and device model are supported before purchasing a license.
: If you have proof of purchase, Apple can often help you regain access to your device or Apple ID account.
: Connect your iPhone to a computer and use iTunes (Windows) or Finder (Mac) to "Restore" the device.