I don’t have a media section in my sidebar. I searched how to add it, which was to add media_source: to the configuration file but that hasn’t done anything. So I’m as stuck as the OP was.
I went through the Automations UI and created a new automation, selected the trigger, chose Play Media for the Action, chose my media player from the list, clicked on the big Pick Media + button, chose a random radio station from the media browser radio station list. Once I confirmed the station played as I wanted, I clicked on the hamburger menu at the upper right of the Automation editor and selected Edit in YAML, copied the yaml there and that’s what I pasted in my earlier response.
I find it easier to do through the website radio-browser.info - go find your radio there, and click on it, in the url you will get the content id , for example:
been trying for 3 days to get this to work. i keep getting Media player does not support browsing media when i try to create an automation to play a radio station with radio browser