How to remove activation lock, when you don’t remember your Apple ID
how To remove a activation lock without your Apple id
iPad (6th gen) WiFi, Cellular
Question marked as
If you forgot your Apple ID - Apple Support
If you forgot your Apple ID password - Apple Support
If you were the original purchaser and can prove it with
a receipt from Apple or Apple authorized iPad retailer showing
the serial number of the iPad, make a genius bar
reservation and bring in the receipt, iPad, and government
issued photo ID to Apple and they may assist in resolving the problem.
If the iPad was purchased used or there is no receipt, the AppleID and passcode must be recovered
It is highly recommended that you make a Genius Bar Reservation to avoid delay at the Apple store
https://www.apple.com/retail/geniusbar/
Activation Lock page: https://al-support.apple.com/#/getsupport