Can I reset the firmware password if I don’t have proof of purchase and have no way to get it or the password from original purchase?

Hello.

So so I worked at a hotel and a guest had left their MacBook. We tried to contact them several times over the course of 6 months to try and send it to them. (We contacted multiple times a week for the first month). We didn’t have an address on file for them and they used a 3rd party booking.

We we were unable to turn it on to even try to get more identifying information.

We held on on to this MacBook for over a year waiting for it to be claimed but no one ever did. (We legally only have to hold items for 90 days). I decided to take the MacBook after getting permission from my boss.

Now i have run into a firmware password issue and I know apple will need proof of purchase which I obviously don’t have.

any other advice for me?