Activation lock

If you cannot secure the cooperation of the previous owner, you cannot bypass this core “anti theft” feature.

Whilst you may have obtained your previously-owned device legitimately, the previous owner failed to follow the correct procedure to prepare the iPad for your re-use. Caveat Emptor.

https://support.apple.com/en-gb/HT201351

https://discussions.apple.com/docs/DOC-250001038

You can't get around Activation Lock in any way without the assistance of the owner who put the lock on the device to begin with. If you purchased a used iPad and whoever you purchased it from is not cooperating with you, there's a very good chance you've been duped and you bought a lost or stolen iPad. Apple won't help. We can't help you.

Try to get your money back or the device will be useless to you.

Read this link --> The All Too Common SAD Reality of Buying … - Apple Community