Select my web radio item via API - possible?

I have Volumio2 running nicely on a pi zero as a web radio, and it works fine. I have a button on my PC desktop which I use to turn it on and off on a given radio station, which again works fine:

curl -X GET http://x.x.x.x/api/v1/commands/?cmd=toggle

But I’d like to expand it a bit and have buttons to chose between the different radio station streams I have stored under My Web Radios. But I can’t see anything in the API that would allow that kind of choice? The closest I can see is to add to the queue, but of course as the playing stream doesn’t end, anything in the queue never plays.

Can this be done, either to select the next stored station, or to pick one from the list? Or would an expansion of the API be required?