API command to get now guide data for specific channel

I am using Channels to stream FTA radio stations around the house from one my HDHRs through my existing wired audio system (I'm old school!)

I want to add the guide data for the Radio channel to the touchscreens that I use to control it.

So I just want to extract the now guide data for a specific channel on the server via an API call.

I've searched around and have got close by experimenting with various API combinations the best I have managed so far is http://192.168.1.8:8089/devices/M3U-HDHR3/guide/now which gives me all of the on now data for one specific device.

I could use that data and search/filter through it for a specific channel's data but I feel sure there must be a way to just get the "on now" guide data for a specific channel number.

Anyone save me another couple of hours experimenting?!

Thanks