Old iPad keeps asking for password to Apple ID that doesn’t exist

I had an iPad years ago that I left in a cupboard when I stopped using it. Today I remembered it and thought about selling it so I got it out and went to reset it. This was met with the request to enter my password for my old Apple ID. This is impossible because:

• That Apple ID no longer exists as the email was changed

• The email also doesn’t exist as it was an old company email

Therefore I cannot reset my password as the email isn’t linked to an account and have no way to reset my iPad

The Model is an iPad Mini Wi-fi (A1432) and running on 9.3.5 (the most up to date software available on the model)