How can I "unlink" a mac that is MDM controlled?

[JPK]

I recently picked up a cheap Mac Mini that was described as

"locked to an MDM server, but this does not affect the operation of the unit."

I am assuming this was a surplus school unit that was previously 'managed'.

Seller nuked and repaved but the MDM link still stays in place.

I have no idea who the original owner was. Can Apple disable this?

Any info is appreciated.

JPK