Question About Siri and Radio

Unfortunately, I do not have a spare device to test iOS 13. For work-related purposes, could I get some more information about Siri and the live radio feature they talked about?

1. Does it require the actual app to play the stations? (i.e. Do I need iHeart actually installed on my phone to ask it to play an iHeart Station?)

2. Is this across all Siri devices? (They talked about Homepods, but does it work on iPhones and Apple TVs?)

3. If this works on iPhones, does it work with Carplay? (i.e. If I asked it to play an iHeart station, would it automatically pull up that station? [If the answer to the first question is that I don't require the app, does that mean that I can ask it to play a station in Carplay without needed the iHeart/TuneIn app?)

I would appreciate any input on this.