Dialogflow link with Google assistant help

I have a few IFTTT which I use with google assistant to trigger home assistant to respond on my main google home.

Me: is anyone watching Plex?
IFTTT: I’ll check
HA (via Main google home using TTS): Yes someone is currently watching Plex (or) No someone is currently watching Plex

Now my problem is I can trigger this on any of my google device, yet the response will allows be on my Main google home. While looking for a solution I came across Dialogflow linked to Home Assistant.

I’ve set up Dialogflow by using the template provided and I can successfully run tests, my issue is linking it to my google assistant account.

I have a few questions;
1, when asking “is anyone watching plex” do I have to use a phrase first before it will trigger
2, does anyone have a good guide or tips how best to set it up?