Welcome to Spotify Community and thanks for reaching out here!
As @Peter has mentioned before, Siri support is available on iPhone, iPad, AirPlay and CarPlay. However, unfortunately, this feature is not available for macOS yet. As a workaround remember that you can still use Siri support on AirPlay.
Also, if you'd like to see the Siri integration for mac as well, I suggest you take a look at the Idea Exchange, to see if someone else has already made a similar suggestion, and if not you can post on your own.
If you have any other further questions or need more help, let me know! I'd love to help!