Monterey MacBook, Airport Express Unit A1264 No Longer Showing Up

I have a new MacBook Pro, with Monterey 12.5. I also have an Apple Express A1264 that I used to stream music from iTunes on my old laptop to a stereo radio. At some point—I don't know when—the Apple Express is no longer showing up. It may have happened when I switched computers, but I feel like I've used it since I switched. Maybe not.

In any case, it's gone now, and I can't figure out a way to pick it up again.

Attached is an image of the Airport Utility window, without the unit showing up. Please help!!