Help with chromecast on gemini box

I have a new gemini box that says it has chromecast
built in. In the apps section, there is no chromecast
app like there was in my genie box. But when I click
on the cast button on my phone or computer, I see a
chromeast connection with the name assigned to the
gemini box. When I click it, it says connecting for
a while but then does not connect.
I spent an hour on the phone with two different directv
people. They spent that time giving me what I believe to
be incorrect information. Here are some of the things
they told me.
1. since the chrome cast app does not appear when 
    clicking the apps button I needed to d/l the       chromecast app from play store.
     tried that and the app on the play store said
     "built in" and the only option was to uninstall
     it.
2. then they told me that I must log in to google for
   it to work. I was logged in. It was clear that I 
    was in the play store. I could see my picture in
     in the upper right corner of the screen indicating
 that I was signed in. I could also see my apps
    and apps that needed upgrades.
3. then the said i need to download the app on my tv not
 on the gemini box.
     I knew this was wrong so I didn't even try
4. then i had to leave home so they said they would
    email instructions on how to access chromeast.
   the email was a link to a directv page that said
   not one word about chromecast.
One thing that I thought might be the issue is that
  the gemini box is connected to the network via
   ethernet. I was told by both people that this could
   NOT be the problem.

Please, can someone here tell me how to use chromecast
on the gemini box?

THANX!!!!