Ambient sounds in Automation?

This support article suggests that Ambient Sounds can be incorporated into scenes and automations:

Listen to seven ambient sounds on HomePod—all without an Apple Music subscription. Use them in your scenes and automations in the Home app, or add an ambient sound to a sleep timer.

Has anybody been able to access these sounds in a way that allows for this? Right now I can only seem to get it by asking Siri on the HomePod.