Google Assistant Webserver

so i have a tv in the loungeroom with a chromecast ultra and a nest mini in my room,
im having trouble broadcasting to the tv, if i click the tv chromecast in HA i can type a message and it plays on the tv… but intterupts currently playing… so i finally got gawebserver going and integrated all working fine.
but broadcasts only come out of the nest mini… i even read up on google assistant and tried variations of the following in the browser trying to get anything to come out of the chromecast

http://192.168.1.117:5000/command?message=“Broadcast to tv, lol”
http://192.168.1.117:5000/command?message=Broadcast to tv, lol
http://192.168.1.117:5000/command?message=“Broadcast to tv”, lol
http://192.168.1.117:5000/command?message=Broadcast to tv, “lol”
http://192.168.1.117:5000/command?message=“Broadcast to tv,” “lol”

now i thought i was onto something here, i tried all of these as depending on the combination i got variations of the broadcast announcement,
if i leave out the comma after the device name the voice on my speaker says "incoming broadcast from chris, “to tv lol”
if i leave it in as the example on Broadcast voice messages to Google Nest or Home devices - Android - Google Nest Help

A room * “Broadcast to [room name] [message].”

  • “Broadcast to the living room, it’s time to start homework.”
    A device * "Broadcast to [device name] [message].”
  • “Broadcast to kitchen display, is dinner ready yet?”

they use a comma, so i thought as per the command that was needed…
i tried just a normal broadcast… ie with no target … only works on nest mini
i tried targeting the room… no luck
all devices are on same wireless network, set up by same phone and linked to same google account
if any1 could help it would be greatly apreciated

edit does it even broadcast to a chromecast like this?