Macbook Pro Airplay 2 support for Sonos Play:5 Speakers
All speakers with this label on the packaging, you can stream to from your MacBook without a Home Pod. 

AirPlay 2 will work on the Sonos Play 5 second generation.


  Enjoy AirPlay 2 on your entire Sonos system. Even though AirPlay 2 is only supported on Sonos One, Beam, Playbase and Play:5 (2nd generation), grouping your other speakers to any of these and you can use AirPlay across your entire home sound system.


(Source)

From the System Requirements:

You can stream from:


  Mac or PC with iTunes 12.8 or later


To update your iTunes version see here.