I have sold my MacBook 2019 and its still registered with Apple ID
I have sold a water damaged MacBook 2019, I was told it cannot be repaired by the computer shop. I sold it as spares only. The person who purchased it seems to want to try and fix it, but says its still registered to my Apple ID.
I have logged on to my Apple ID and its not under my managed devices, can anyone help explain why Apple store are saying its still registered with my Apple ID and how do I remove it properly? The MacBook obviously will not turn on.