found iphone 15 pro max in a dumpster what to do?

My neighbor found an iphone 15 pro max in the original box unlocked with no numbers or information on it in perfect working condition in a dumpster. I checked on a website to see if it was lost or stolen and it says it is blacklisted. We really would like to return it to the true owner but have no idea how to do that. Any suggestions? It is in perfect condition and is a new phone that appears to have never been used just hate to see it wasted.

Oh I see by the answers there is nothing to be done. How sad. Oh well at least we tried. Thank you all for the quick responses. How strange that someone would throw it away.