Remove activation lock

If this is a used device, the previous owner needs to log out of iCloud or go to https://www.icloud.com/find/ and erase the device, then remove it from their account. If they won't do that, the device is useless. Apple won't unlock it.

Turn off Activation Lock - Apple Support.     

If you are the original owner, contact Apple. Apple can remove the ID  if provided the required paperwork. 

Request additional support for unlocking your device

Either take the device, the original purchase receipt with the serial number, and a photo ID to the nearest Apple Store (if it has reopened)

Genius Bar Reservation and Apple Support Options - Apple.    

or contact Apple ID Support. 

 Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.      (Link doesn’t always load)   

Get Support   https://getsupport.apple.com        Work through the screens to get a chat option. 

Apple Support schedule phone call        

https://twitter.com/AppleSupport       People have posted it may take an hour or more to get a response.