Create ML - record microphone

In the Training Sound Classification Models in Create ML talk in WWDC 2019, at timecode 7:23, Dan Klingler says "We've added a button here that has record microphone." Unfortunately in the video we can't see how he got the record button to appear instead of the play button (it automatically returns to the play button when he stops the record at 9:12). Does anyone know how to get this record button to appear? Am I missing something or is it not available in the current beta?