Adding Paramount Plus to my Vizio TV

I called DirectTV & was told I need to pay for the app.  I totally understand that.  But your platform is through Yahoo & the app is NOT listed under the app store for Paramount Plus.  I tried going to Yahoo to add it because it states I need a code!  Where do I get the code??? - Yahoo has  NO idea either!!!  Why does it have to be this difficult???  I also went to Paramount Plus & ordered the app but trying to get it installed on the TV has taken hours & I am still no closer to adding the app to the TV.  All I want to know is how the heck do I add the app to the TV if it is not included on the Direct TV platform???