101894282607 case trying to unlock this device iCloud lock it purchased online

Go to Apple store get Proof of Ownership, copy of Original Invoice (from the Original First Purchase) and Present with your Id to Genius bar (It might take time). No Original Invoice ? Call Ebay send back to Seller get refund! (it might not be his) or get the ICloud ID removed from previous Account in ICloud Console from previous owner!

Mery xmas

Not with a second-hand purchase, no. You'll need the original owner to unlock the device for you.

You don't. Return it or recycle it responsibly, it will never work for you.