Playing iPhone music on non-synched Macbook

Yesterday I was forced to upgrade the OS to Monterey on my work MacBook Pro. iTunes went away and was replaced instead with Music.app. When I had iTunes, I could plug my iPhone, which is synched to my personal computer, and play/control its music library from the MacBook and hear it on my desktop speakers. Now, none of that works. Music.app wants me to sync to the wrong library on the wrong computer.

How do I fix this?

On a side note, Apple has become terrible. I regret I ever purchased any music on iTunes. I just want to listen while I work and for no good reason you have to make that difficult.